Detected on Windows Vista: *ALL* examples renders outside the widget. This occurs with GTK 2.14.x, 2.16.x. Detected in C examples and Python examples. There are only 2 examples without this problem: color.exe/color.py and simple-mixed.exe/simple-mixed.py. Both seems use MODE_SIGNLE instead of MODE_DOUBLE (buffering mode). Tested with versions of gtkglext-1.0.0.
The same examples on OpenBSD works good - without this bug (but I ran under tiling window manager, so nothing known about floating mode windows, I suppose it's all right anyway under Unix).
gtkglext-1.2.0 has this bug too
Win7 too