diff --git a/ChangeLog b/ChangeLog
index 16d2455ee..4a5af17ba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,17 @@
 	content.
 	* Source/NSPredicate.m: Revert to previous version as last change
 	contained broken code and wouldn't compile.
+	* Source/NSKeyValueCoding.m:
+	* Source/GSArray.m:
+	* Source/GSFFCallInvocation.m:
+	* Source/NSInvocation.m:
+	* Source/NSCoder.m:
+	* Source/NSObject.m:
+	* Source/Additions/GSCategories.m:
+	* Headers/Foundation/NSLock.h:
+	* Tools/AGSHtml.m:
+	* Tools/autogsdoc.m:
+	Use casts to avoid spurious warnings from gcc-4.1
 
 2006-05-15  Fred Kiefer <FredKiefer@gmx.de>
 
diff --git a/Headers/Foundation/NSLock.h b/Headers/Foundation/NSLock.h
index 3d4c332b8..674723cc7 100644
--- a/Headers/Foundation/NSLock.h
+++ b/Headers/Foundation/NSLock.h
@@ -222,7 +222,7 @@
  * </example>
  */
 #define GS_INITIALIZED_LOCK(IDENT,CLASSNAME) \
-           (IDENT != nil ? IDENT : [CLASSNAME newLockAt: &IDENT])
+           (IDENT != nil ? (id)IDENT : (id)[CLASSNAME newLockAt: &IDENT])
 
 /**
  *  Defines the <code>newLockAt:</code> method.
diff --git a/Source/Additions/GSCategories.m b/Source/Additions/GSCategories.m
index 3e6a05a96..a2e551517 100644
--- a/Source/Additions/GSCategories.m
+++ b/Source/Additions/GSCategories.m
@@ -992,7 +992,7 @@ static void MD5Transform (uint32_t buf[4], uint32_t const in[16])
    * Ordering objects by their address is pretty useless,
    * so subclasses should override this is some useful way.
    */
-  if (self > anObject)
+  if ((id)self > anObject)
     {
       return NSOrderedDescending;
     }
diff --git a/Source/GSArray.m b/Source/GSArray.m
index 4184ee8e5..5f5b77aa9 100644
--- a/Source/GSArray.m
+++ b/Source/GSArray.m
@@ -19,7 +19,8 @@
 
    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 USA.
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02111 USA.
 
    $Date$ $Revision$
    */
@@ -121,9 +122,9 @@ static Class	GSInlineArrayClass;
 
 + (id) allocWithZone: (NSZone*)zone
 {
-  GSArray	*array = NSAllocateObject(self, 0, zone);
+  GSArray	*array = (GSArray*)NSAllocateObject(self, 0, zone);
 
-  return array;
+  return (id)array;
 }
 
 - (id) copyWithZone: (NSZone*)zone
diff --git a/Source/GSFFCallInvocation.m b/Source/GSFFCallInvocation.m
index b6785ead0..bc491be9e 100644
--- a/Source/GSFFCallInvocation.m
+++ b/Source/GSFFCallInvocation.m
@@ -18,7 +18,8 @@
 
    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 USA.
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02111 USA.
    */
 #include "Foundation/NSException.h"
 #include "Foundation/NSCoder.h"
@@ -684,8 +685,8 @@ GSFFCallInvokeWithTargetAndImp(NSInvocation *_inv, id anObject, IMP imp)
     {
       GSMethod method;
       method = GSGetMethod((GSObjCIsInstance(_target)
-                            ? GSObjCClass(_target)
-                            : _target),
+                            ? (id)GSObjCClass(_target)
+                            : (id)_target),
                            _selector,
                            GSObjCIsInstance(_target),
                            YES);
diff --git a/Source/NSCoder.m b/Source/NSCoder.m
index ed96a8d90..ef49c62af 100644
--- a/Source/NSCoder.m
+++ b/Source/NSCoder.m
@@ -123,8 +123,9 @@
 
 - (void) encodePropertyList: (id)plist
 {
-  id    anObject = plist ? [NSSerializer serializePropertyList: plist] : nil;
+  id    anObject;
 
+  anObject = plist ? (id)[NSSerializer serializePropertyList: plist] : nil;
   [self encodeValueOfObjCType: @encode(id) at: &anObject];
 }
 
diff --git a/Source/NSInvocation.m b/Source/NSInvocation.m
index 9f4f9c75d..5b9b05d40 100644
--- a/Source/NSInvocation.m
+++ b/Source/NSInvocation.m
@@ -19,7 +19,8 @@
 
    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 USA.
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02111 USA.
 
    <title>NSInvocation class reference</title>
    $Date$ $Revision$
@@ -602,8 +603,8 @@ _arg_addr(NSInvocation *inv, int index)
     {
       GSMethod method;
       method = GSGetMethod((GSObjCIsInstance(_target)
-			    ? GSObjCClass(_target)
-			    : _target),
+			    ? (id)GSObjCClass(_target)
+			    : (id)_target),
 			   _selector,
 			   GSObjCIsInstance(_target),
 			   YES);
diff --git a/Source/NSKeyValueCoding.m b/Source/NSKeyValueCoding.m
index 293a322a7..75b38eebd 100644
--- a/Source/NSKeyValueCoding.m
+++ b/Source/NSKeyValueCoding.m
@@ -217,11 +217,9 @@ static id ValueForKey(NSObject *self, const char *key, unsigned size)
 - (id) handleQueryWithUnboundKey: (NSString*)aKey
 {
   NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
-				     self,
-				     @"NSTargetObjectUserInfoKey",
-				     (aKey ? aKey : @"(nil)"),
-				     @"NSUnknownUserInfoKey",
-				     nil];
+    self, @"NSTargetObjectUserInfoKey",
+    (aKey ? (id)aKey : (id)@"(nil)"), @"NSUnknownUserInfoKey",
+    nil];
   NSException *exp = [NSException exceptionWithName: NSUndefinedKeyException
 				  reason: @"Unable to find value for key"
 				  userInfo: dict];
@@ -235,11 +233,9 @@ static id ValueForKey(NSObject *self, const char *key, unsigned size)
 - (void) handleTakeValue: (id)anObject forUnboundKey: (NSString*)aKey
 {
   NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
-				     (anObject ? anObject : @"(nil)"),
-				     @"NSTargetObjectUserInfoKey",
-				     (aKey ? aKey : @"(nil)"),
-				     @"NSUnknownUserInfoKey",
-				     nil];
+    (anObject ? (id)anObject : (id)@"(nil)"), @"NSTargetObjectUserInfoKey",
+    (aKey ? (id)aKey : (id)@"(nil)"), @"NSUnknownUserInfoKey",
+    nil];
   NSException *exp = [NSException exceptionWithName: NSUndefinedKeyException
 				  reason: @"Unable to set value for key"
 				  userInfo: dict];
@@ -345,11 +341,9 @@ static id ValueForKey(NSObject *self, const char *key, unsigned size)
     }
 
   dict = [NSDictionary dictionaryWithObjectsAndKeys:
-				     (anObject ? anObject : @"(nil)"),
-				     @"NSTargetObjectUserInfoKey",
-				     (aKey ? aKey : @"(nil)"),
-				     @"NSUnknownUserInfoKey",
-				     nil];
+    (anObject ? (id)anObject : (id)@"(nil)"), @"NSTargetObjectUserInfoKey",
+    (aKey ? (id)aKey : (id)@"(nil)"), @"NSUnknownUserInfoKey",
+    nil];
   exp = [NSException exceptionWithName: NSInvalidArgumentException
 				reason: @"Unable to set nil value for key"
 			      userInfo: dict];
@@ -801,11 +795,9 @@ static id ValueForKey(NSObject *self, const char *key, unsigned size)
       return [self handleQueryWithUnboundKey: aKey];
     }
   dict = [NSDictionary dictionaryWithObjectsAndKeys:
-				     self,
-				     @"NSTargetObjectUserInfoKey",
-				     (aKey ? aKey : @"(nil)"),
-				     @"NSUnknownUserInfoKey",
-				     nil];
+    self, @"NSTargetObjectUserInfoKey",
+    (aKey ? (id)aKey : (id)@"(nil)"), @"NSUnknownUserInfoKey",
+    nil];
   exp = [NSException exceptionWithName: NSUndefinedKeyException
 				reason: @"Unable to find value for key"
 			      userInfo: dict];
diff --git a/Source/NSObject.m b/Source/NSObject.m
index e891b8cdf..ddb30d22b 100644
--- a/Source/NSObject.m
+++ b/Source/NSObject.m
@@ -18,7 +18,8 @@
 
    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111 USA.
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02111 USA.
 
    <title>NSObject class reference</title>
    $Date$ $Revision$
@@ -1388,8 +1389,9 @@ GSDescriptionForClassMethod(pcl self, SEL aSel)
 		format: @"%@ null selector given", NSStringFromSelector(_cmd)];
 
   mth = GSGetMethod(self, aSelector, YES, YES);
-  return mth ? [NSMethodSignature signatureWithObjCTypes:mth->method_types]
-    : nil;
+  if (mth == 0)
+    return nil;
+  return [NSMethodSignature signatureWithObjCTypes:mth->method_types];
 }
 
 /**
@@ -2075,8 +2077,9 @@ GSDescriptionForClassMethod(pcl self, SEL aSel)
 		format: @"%@ null selector given", NSStringFromSelector(_cmd)];
 
   mth = GSGetMethod(self, aSelector, YES, YES);
-  return mth ? [NSMethodSignature signatureWithObjCTypes:mth->method_types]
-    : nil;
+  if (mth == 0)
+    return nil;
+  return [NSMethodSignature signatureWithObjCTypes:mth->method_types];
 }
 
 - (IMP) methodFor: (SEL)aSel
diff --git a/Tools/AGSHtml.m b/Tools/AGSHtml.m
index 7e8455a0e..08fbe5cc1 100644
--- a/Tools/AGSHtml.m
+++ b/Tools/AGSHtml.m
@@ -2290,7 +2290,7 @@ static NSString		*mainFont = nil;
 {
   NSArray	*a;
   NSMutableString *ivarBuf = ivarsAtEnd ?
-    [NSMutableString stringWithCapacity: 1024] : nil;
+    (id)[NSMutableString stringWithCapacity: 1024] : nil;
   NSDictionary	*prop = [node attributes];
 
   node = [node firstChildElement];
diff --git a/Tools/autogsdoc.m b/Tools/autogsdoc.m
index fa4da63bd..f90d596b3 100644
--- a/Tools/autogsdoc.m
+++ b/Tools/autogsdoc.m
@@ -2203,7 +2203,7 @@ main(int argc, char **argv, char **env)
 		    {
 		      NSLog(@"Replace %@ with %@",
 			[s substringWithRange: replace],
-			repstr ? repstr : @"self");
+			repstr ? (id)repstr : (id)@"self");
 		    }
 		  if (repstr != nil)
 		    {