May be it was bug in Qemu emulator itself OR Mesa's swrast doesn't work too well with 24/24 (as opposed to 24/32) screen/framebuffer (bpp/fbbpp) configuration.
At least Ubuntu 10.04 LiveCD show this problem, too (it uses mesa 7.6.1-rc2-1ubuntu1).
May be it was bug in Qemu emulator itself OR Mesa's swrast doesn't work too well with 24/24 (as opposed to 24/32) screen/framebuffer (bpp/fbbpp) configuration.
At least Ubuntu 10.04 LiveCD show this problem, too (it uses mesa 7.6.1-rc2- 1ubuntu1) .