I think it's partial texture updates and pixel_datarange extension. Ogl works fine here with ati. I'll try to catch Kronuz on irc to see what we can do about it...I think he has a nvidia card, I wonder why he hasn't noticed the problem if this really is the problem.
It's weird, it seems to work fine here too (nVIDIA GeForce FX5200) ...although for some strange reason it freezes some times (but that happens always, when I'm using OpenGL in any program).
Edit: I tried it on other computer with nVIDIA Geforece MX440, and there seems to be some issues with the partial update; also, I found it froze there too... hmm
Edit: I've created a new patch after detecting a bug in the OpenGL update code. Hopefully this solves the issue.
@Leolo: Okay, here's the binary attached, please try it and tell me if the problem persists. (This build doesn't include the timesync patch as my previous builds, as I've found it doesn't work always... and since it's not part of my patch, I've stripped it out)
Qbix: Attachment removed
"Time is of the essence"