Running current git of mesa master (compiled without libdrm_radeon and without KMS) I am getting the following assertion when trying to play the "aqueducts" maps of sauerbraten (when run with command line option "-f1", which is the default) game (under DMSP maps).

My card:
GL_RENDERER   = Mesa DRI R300 (RV530 71C5) 20090101 x86/MMX/SSE2 TCL

$ sauerbraten -f1
Using home directory: /home/fabio/.sauerbraten
init: sdl
init: enet
init: video: mode
init: video: misc
init: gl
Renderer: Mesa DRI R300 (RV530 71C5) 20090101 x86/MMX/SSE2 TCL (DRI R300 Project)
Driver: 1.4 Mesa 7.6-devel
WARNING: No framebuffer object support. (reflective water may be slow)
WARNING: No occlusion query support! (large maps may be SLOW)
WARNING: Non-power-of-two textures not supported!
Rendering using the OpenGL 1.5 assembly shader path.
init: console
init: gl: effects
init: world
init: sound
init: cfg
your team is: 
init: localconnect
init: mainloop
read map packages/base/metl4.ogz (0.1 seconds)
Mining Station by metlslime
game mode is ffa/default
read map packages/base/aqueducts.ogz (0.3 seconds)
Abandoned_Hilltop_Aqueducts
game mode is DMSP
sauer_client: radeon_common.c:1016: radeon_validate_bo: Assertion `radeon->state.validated_bo_count < 32' failed.
Aborted