diff --git a/Tests/base/NSKVOSupport/general.m b/Tests/base/NSKVOSupport/general.m
index e69ac332e..3339d8987 100644
--- a/Tests/base/NSKVOSupport/general.m
+++ b/Tests/base/NSKVOSupport/general.m
@@ -1462,7 +1462,7 @@ ObserveAllProperties()
   START_SET("ObserveAllProperties");
   FLAKY_ON_GCC_START
 
-  TestKVOObject   *observed = [[TestKVOObject alloc] init];
+  TestKVOObject   *observed = AUTORELEASE([[TestKVOObject alloc] init]);
   TestKVOObserver *observer = [[[TestKVOObserver alloc] init] autorelease];
 
   [observed addObserver:observer
@@ -2102,8 +2102,8 @@ SetValueForKeyPropertyNotification()
   // not get two notifications for the same change.
   START_SET("SetValueForKeyPropertyNotification");
 
-  TestKVOObject   *observed = [TestKVOObject new];
-  TestKVOObserver *observer = [TestKVOObserver new];
+  TestKVOObject   *observed = AUTORELEASE([TestKVOObject new]);
+  TestKVOObserver *observer = AUTORELEASE([TestKVOObserver new]);
 
   [observed addObserver:observer
              forKeyPath:@"basicObjectProperty"
diff --git a/Tests/base/NSMutableArray/general.m b/Tests/base/NSMutableArray/general.m
index 983ac3f5a..dcf2c2daf 100644
--- a/Tests/base/NSMutableArray/general.m
+++ b/Tests/base/NSMutableArray/general.m
@@ -11,14 +11,14 @@ int main()
   val2 = @"A Goodbye";
   val3 = @"Testing all strings";
   
-  vals1 = [[NSMutableArray arrayWithObject: val1] retain];
+  vals1 = [NSMutableArray arrayWithObject: val1];
   [vals1 addObject: val2];
   vals2 = AUTORELEASE([vals1 mutableCopy]);
   [vals2 addObject: val2];
   vals3 = AUTORELEASE([vals2 mutableCopy]);
   [vals3 addObject: val3];
   
-  obj = [NSMutableArray new];
+  obj = [NSMutableArray array];
   arr = obj;
   PASS(obj != nil && [obj isKindOfClass:[NSMutableArray class]] && [obj count] == 0,
        "-count returns zero for an empty array");
diff --git a/Tests/base/NSMutableDictionary/general.m b/Tests/base/NSMutableDictionary/general.m
index 9a5f5a147..c775c6687 100644
--- a/Tests/base/NSMutableDictionary/general.m
+++ b/Tests/base/NSMutableDictionary/general.m
@@ -97,7 +97,7 @@ int main()
        [obj count] == 0,
        "-description gives us a text property-list");
   
-  dict = [[NSMutableDictionary dictionaryWithObjects:vals1 forKeys:keys1] retain];
+  dict = [NSMutableDictionary dictionaryWithObjects:vals1 forKeys:keys1];
   PASS(dict != nil && 
        [dict isKindOfClass:[NSMutableDictionary class]] && 
        [dict count] == 2,
diff --git a/Tests/base/NSMutableSet/basic.m b/Tests/base/NSMutableSet/basic.m
index 0ed08479c..5223a3c05 100644
--- a/Tests/base/NSMutableSet/basic.m
+++ b/Tests/base/NSMutableSet/basic.m
@@ -6,7 +6,7 @@
 int main()
 {  
   NSAutoreleasePool   *arp = [NSAutoreleasePool new];
-  NSMutableSet *testObj = [NSMutableSet new];
+  NSMutableSet *testObj = [NSMutableSet set];
   test_NSObject(@"NSMutableSet", [NSArray arrayWithObject:testObj]);
   test_NSCoding([NSArray arrayWithObject:testObj]);
   test_NSCopying(@"NSSet",@"NSMutableSet",
diff --git a/Tests/base/NSOperation/concurrent.m b/Tests/base/NSOperation/concurrent.m
index 480d86bcb..e7a17f897 100644
--- a/Tests/base/NSOperation/concurrent.m
+++ b/Tests/base/NSOperation/concurrent.m
@@ -141,6 +141,7 @@ int main()
     {
       obj = [[MyOperation alloc] initWithValue: i];
       [a addObject: obj];
+      RELEASE(obj);
       [q addOperation: obj];
     }
   [q waitUntilAllOperationsAreFinished];
@@ -157,7 +158,7 @@ int main()
 	}
     }
   PASS((ran == want), "many operations, all were performed")
-  PASS((f - s) < 0.1, "many operations, duration was reasonably small")
+  PASS((f - s) < 0.5, "concurrent test duration")
 
   // multiple concurrent operations
   [q setMaxConcurrentOperationCount: 5];
@@ -178,6 +179,7 @@ int main()
       PASS(([obj getCalculation] == (2*i)), "operation was performed");
     }
 
+  RELEASE(q);
   END_SET("concurrent operations")
   return 0;
 }
diff --git a/Tests/base/NSOperation/perform.m b/Tests/base/NSOperation/perform.m
index 069e82094..374a71277 100644
--- a/Tests/base/NSOperation/perform.m
+++ b/Tests/base/NSOperation/perform.m
@@ -59,7 +59,7 @@ int main()
   [q waitUntilAllOperationsAreFinished];
   f = [NSDate timeIntervalSinceReferenceDate];
   PASS([o counter] == want, "expected number of operations")
-  PASS((f - s) < 0.1, "duration was reasonable")
+  PASS((f - s) < 0.5, "sequential test duration")
 
   [o reset];
   [q addOperationWithTarget: o
diff --git a/Tests/base/NSOperation/threads.m b/Tests/base/NSOperation/threads.m
index 07ef7f1a0..c5359327f 100644
--- a/Tests/base/NSOperation/threads.m
+++ b/Tests/base/NSOperation/threads.m
@@ -224,14 +224,17 @@ int main()
 
   PASS(([NSOperationQueue currentQueue] == [NSOperationQueue mainQueue]), "current queue outside -main is main queue");
   PASS(([NSOperationQueue mainQueue] != nil), "main queue is not nil");
+
   obj = [OpFlag new];
   [q addOperation: obj];
   [q waitUntilAllOperationsAreFinished];
   PASS(([obj isFinished] == YES), "main queue runs an operation");
   PASS(([obj thread] != [NSThread currentThread]),
     "operation ran in other thread");
+  RELEASE(obj);
 
   [q setSuspended: YES];
+
   obj = [OpFlag new];
   [q addOperation: obj];
   [NSThread sleepForTimeInterval: 0.1];
@@ -239,7 +242,7 @@ int main()
   [q setSuspended: NO];
   [q waitUntilAllOperationsAreFinished];
   PASS(([obj isFinished] == YES), "unsuspend works");
-  [obj release];
+  RELEASE(obj);
 
   [q setMaxConcurrentOperationCount: 0];
   obj = [OpFlag new];