gl video output problem

[uncle bob]

Whenever I select "gl" as my video output strange things happen. No right-click menu, when I move the mouse in full screen, the picture flickers, especially when I hover over full screen controller. Everything works fine with "directx" or "direct3d" selected. I really like "gl" output because the subtitles look very nice.

OS: Win 7 x64
VGA: AMD Radeon HD 5770 (with the latest drivers)

Any help would be greatly appreciated!