A friend's machine (PCQ7.1) hangs mysteriously after an X crash. What we found was this:
When running at a high resolution, there is insufficient memory to load the direct rendering manager (drm), and the server runs properly.
When the resolution is lowered, there is more video memory available, and hence the drm is loaded. In particular, the RENDER extension, which is used for Anti Aliased fonts.
When drm is loaded, OpenGL programs crash X and the entire system. When drm is not loaded, OpenGL programs run slowly.
Any ideas?
The card is Matrox Millenium with 8MB VRAM.
Philip