Xorg-HEAD with XGL branch with Mesa 6.5 issues

[Shawn Starr]

Mesa 6.5 implementation error: Unexpected format 0xa77f4625 in _mesa_source_buffer_exists
Please report at bugzilla.freedesktop.org

Xgl: tnl/t_vb_arbprogram.c:1279: run_arb_vertex_program: Assertion `p' failed.

If I build the Xgl branch install it _then_ install Xorg-HEAD. Xgl works rather well, except if I start certain applications: firefox or konsole it crashes out and dumps this to log. 

Thanks, 

Shawn.