Hardware: mobility Radeon 9000 / RV250Lf on Intel-AGP (i855PM) 
DRI CVS 2004-06-25 (Binary Snapshot) / XF86 4.3 / Debian Sarge 
 
When starting with a new map in GtkRadiant, nothing can be seen in the 2d view 
except from the normal grid. You map looks as if it was empty. Furthermore, 
the textures in the 3d view are distorted. 
 
When trying to open an existing map-file (for example q3dm7sample.map which is 
shipped with gtkradiant), the program crashes. This debug-message is printed 
on the console: 
r200_vtxfmt.c:1052: r200VtxFmtFlushVertices: Assertion `rmesa->dma.flush == 0 
|| rmesa->dma.flush == flush_prims' failed. 
 
It also crashes when creating some brushes on an empty map after some time, 
sometimes even on the first click into the 2d view. There's no message given 
on the console. 
 
These bugs don't appear with the drivers shipped with XF86 4.3. But another 
bug (which might be fixed now but I couldn't check because of the above bugs) 
appeared with 4.3's drivers: Sometimes the textures seemed to be completely 
screwed-up (especially after starting Quake3 with Radiant left open in the 
background), which means that in the 3d preview, objects had wrong textures 
(or no textures at all) on them (like randomly assigning OpenGL texture-ids). 
 
You can get gtkRadiant at http://www.qeradiant.com/