PDR strange behaviour...


I have mada a player that can play MPEG2 files using OpenGL as renderer. To speedup uploading texture stage, I have use PDR. But now I have strange problem.
In my player app, rendering are implemented in separate thread. Video decoder (from dshow) run in another thread and copy frame pixel data directly to PDR memory. After that, rendering thread use this data and copy in rectangle texture. I have made sync control while acces to PDR buffer from different thread to preserve read/write collision.
Before framne rendering app call glFlushPixelDataRangeNV.

Everything play well, until I try to move or resize player window. If I enable vsync in driver pages, machine freeze for a few seconds (even mouse can’t be moved) and after thar work well.
If vsync are disabled everything is OK.

If I try to avoid glFlushPixelDataRangeNV app work fine, but sometime image are not renderer correctly.

Application freeze in SwapBuffers() call.
In single threaded application there is no such problem with PDR.

Did someone know something about this?

Im using P4-2.4, GF4800SE, FW56.64, WinXP SP1