Producing a useful back-trace via gdb would be the most important thing. Looks like you're using a 64 bit system, I don't know if any of the developers is testing this on 64 bit (I'm certainly not). So it might be a rather simple thing that you can fix yourself and provide a patch for.
I'm using 64 bit so it is probably RS690-specific
IIRC, gallium is currently broken on cards without vertex shaders like your RS690.
Just my 2 cents:
radeon driver works for me, but its performance isn't as half as with classic driver.
OpenGL vendor string: DRI R300 Project
OpenGL renderer string: Mesa DRI R300 (RV350 4152) 20090101 x86/MMX/SSE2 TCL DRI2
OpenGL version string: 1.5 Mesa 7.8-devel
glxgears
7116 frames in 5.0 seconds = 1423.112 FPS
7295 frames in 5.0 seconds = 1458.875 FPS
7301 frames in 5.0 seconds = 1460.139 FPS
7434 frames in 5.0 seconds = 1486.580 FPS
OpenGL vendor string: X.Org R300 Project
OpenGL renderer string: Gallium 0.4 on RV350
OpenGL version string: 2.1 Mesa 7.8-devel
OpenGL shading language version string: 1.20
glxgears
3490 frames in 5.0 seconds = 697.942 FPS
3452 frames in 5.0 seconds = 690.341 FPS
3549 frames in 5.0 seconds = 709.742 FPS
3468 frames in 5.0 seconds = 693.542 FPS
3484 frames in 5.0 seconds = 696.742 FPS
Well, that's not to say the G3D driver should be faster for other applications - but might. It wouldn't surprise me if it isn't though since the driver barely is optimized, yet.
(damn 1 minute edit limit)