Locking assertion failure.  Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb7c7b767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb7c7b8b1]
#2 /usr/lib/libX11.so.6 [0xb7ecbd11]
#3 Xdmx(__glXRenderLarge+0x83) [0x817e6f3]
#4 Xdmx [0x817a3ba]
#5 Xdmx [0x810474e]
#6 Xdmx(Dispatch+0x2bf) [0x80b915f]
#7 Xdmx(main+0x48b) [0x809ed6b]
#8 /lib/libc.so.6(__libc_start_main+0xe0) [0xb7c93390]
#9 Xdmx [0x8073121]