diff --git a/ChangeLog b/ChangeLog
index a400318..83d3582 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-02-10 Eric Wasylishen <ewasylishen@gmail.com>
+
+	* Source/x11/XGServerWindow.m:
+	* Source/x11/XGServerEvent.m:
+	* Headers/x11/XGGeneric.h: Handle horizontal scrolling events
+
 2010-02-07 03:37-EST Gregory John Casamento <greg.casamento@gmail.com>
 
 	* Headers/win32/WIN32Server.h: Remove HOTKEY method.
diff --git a/Headers/x11/XGGeneric.h b/Headers/x11/XGGeneric.h
index ec0e67f..e84cbac 100644
--- a/Headers/x11/XGGeneric.h
+++ b/Headers/x11/XGGeneric.h
@@ -117,6 +117,8 @@ struct XGGeneric {
   unsigned char		rMouse;
   unsigned char		upMouse;
   unsigned char		downMouse;
+  unsigned char		scrollLeftMouse;
+  unsigned char		scrollRightMouse;
   int			lMouseMask;
   int			mMouseMask;
   int			rMouseMask;
diff --git a/Source/x11/XGServerEvent.m b/Source/x11/XGServerEvent.m
index df1e278..0697437 100644
--- a/Source/x11/XGServerEvent.m
+++ b/Source/x11/XGServerEvent.m
@@ -402,6 +402,7 @@ posixFileDescriptor: (NSPosixFileDescriptor*)fileDescriptor
         }
         generic.lastClick = xEvent.xbutton.time;
         [self setLastTime: generic.lastClick];
+	deltaX = 0.0;
         deltaY = 0.0;
 
         if (xEvent.xbutton.button == generic.lMouse)
@@ -435,6 +436,20 @@ posixFileDescriptor: (NSPosixFileDescriptor*)fileDescriptor
             eventType = NSScrollWheel;
             buttonNumber = generic.downMouse;
           }
+        else if (xEvent.xbutton.button == generic.scrollLeftMouse
+          && generic.scrollLeftMouse != 0)
+          {
+            deltaX = -1.;
+            eventType = NSScrollWheel;
+            buttonNumber = generic.scrollLeftMouse;
+          }
+        else if (xEvent.xbutton.button == generic.scrollRightMouse
+          && generic.scrollRightMouse != 0)
+          {
+            deltaX = 1.;
+            eventType = NSScrollWheel;
+            buttonNumber = generic.scrollRightMouse;
+          }
         else
           {
             break;                /* Unknown button */
@@ -484,7 +499,7 @@ posixFileDescriptor: (NSPosixFileDescriptor*)fileDescriptor
                      clickCount: clickCount
                      pressure: 1.0
                      buttonNumber: buttonNumber /* FIXME */
-                     deltaX: 0.
+                     deltaX: deltaX
                      deltaY: deltaY
                      deltaZ: 0.];
         break;
diff --git a/Source/x11/XGServerWindow.m b/Source/x11/XGServerWindow.m
index 1b38515..21c2949 100644
--- a/Source/x11/XGServerWindow.m
+++ b/Source/x11/XGServerWindow.m
@@ -1295,13 +1295,15 @@ _get_next_prop_new_event(Display *display, XEvent *event, char *arg)
 - (void) _setupMouse
 {
   int			numButtons;
-  unsigned char		mouseNumbers[5];
-  unsigned char		buttons[5] = {
+  unsigned char		mouseNumbers[7];
+  unsigned char		buttons[7] = {
 			  Button1,
 			  Button2,
 			  Button3,
 			  Button4,
-			  Button5
+			  Button5,
+			  6,
+			  7
 			};
   int			masks[5] = {
 			  Button1Mask,
@@ -1314,15 +1316,21 @@ _get_next_prop_new_event(Display *display, XEvent *event, char *arg)
    * Get pointer information - so we know which mouse buttons we have.
    * With a two button
    */
-  numButtons = XGetPointerMapping(dpy, mouseNumbers, 5);
-  if (numButtons > 5)
+  numButtons = XGetPointerMapping(dpy, mouseNumbers, 7);
+  if (numButtons > 7)
     {
-      NSDebugLLog(@"XGTrace", @"Warning - mouse/pointer seems to have more than 5 buttons "
-	@"(%d) - just using one to five", numButtons);
-      numButtons = 5;
+      NSDebugLLog(@"XGTrace", @"Warning - mouse/pointer seems to have more than 7 buttons "
+	@"(%d) - just using one to seven", numButtons);
+      numButtons = 7;
     }
   generic.lMouse = buttons[0];
   generic.lMouseMask = masks[0];
+  if (numButtons >= 7)
+    {
+      generic.scrollLeftMouse = buttons[5];
+      generic.scrollRightMouse = buttons[6];
+    }
+
   if (numButtons >= 5)
     {
       generic.upMouse = buttons[3];