diff --git a/ChangeLog b/ChangeLog
index 2ae04cf..48b436f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2010-07-25  Eric Wasylishen <ewasylishen@gmail.com>
+
+	* Source/win32/w32_GLContext.m:
+	* Source/x11/XGGLContext.m:
+	Apply fix for bug 29705: OpenGL subwindow positioning error
+	(OpenGL subwindow position was incorrectly calculated when
+	the window content view was flipped)
+
 2010-07-25 Fred Kiefer <FredKiefer@gmx.de>
 
 	* Source/x11/XGServerEvent.m:
diff --git a/Source/win32/w32_GLcontext.m b/Source/win32/w32_GLcontext.m
index 650e5a4..7f0bb11 100644
--- a/Source/win32/w32_GLcontext.m
+++ b/Source/win32/w32_GLcontext.m
@@ -137,6 +137,10 @@ LRESULT CALLBACK win32SubwindowProc(
        * we must therefore use content view coordinates.
        */
       rect = [view convertRect: [view bounds] toView: [[attached window] contentView]];
+      if ([[[attached window] contentView] isFlipped])
+        {
+          rect.origin.y = NSHeight([[[attached window] contentView] frame]) - (rect.size.height + rect.origin.y);
+        }
     }
   else
     {
@@ -210,6 +214,10 @@ LRESULT CALLBACK win32SubwindowProc(
        */
       rect = [attached convertRect: [attached bounds]
 			    toView: [[attached window] contentView]];
+      if ([[[attached window] contentView] isFlipped])
+        {
+          rect.origin.y = NSHeight([[[attached window] contentView] frame]) - (rect.size.height + rect.origin.y);
+        }
     }
   else
     {
diff --git a/Source/x11/XGGLContext.m b/Source/x11/XGGLContext.m
index 985825d..04d47a2 100644
--- a/Source/x11/XGGLContext.m
+++ b/Source/x11/XGGLContext.m
@@ -104,6 +104,10 @@
        */
       rect = [view convertRect: [view bounds]
                         toView: [window contentView]];
+      if ([[window contentView] isFlipped])
+        {
+          rect.origin.y = NSHeight([[window contentView] frame]) - (rect.size.height + rect.origin.y);
+        }
     }
   else
     {
@@ -194,6 +198,10 @@
        */
       rect = [attached convertRect: [attached bounds]
 			    toView: [[attached window] contentView]];
+      if ([[[attached window] contentView] isFlipped])
+        {
+          rect.origin.y = NSHeight([[[attached window] contentView] frame]) - (rect.size.height + rect.origin.y);
+        }
     }
   else
     {