Bug#428109: makes e. g. supertux slow, quiting crashes X

Yes, libgl1-mesa-dri is intsalled.

However the symptoms have recently stopped. Whilst attempting to diagnose the problem, some one on #debian-x suggested that I re-install libgl1-mesa-glx. Before this, the glx was not that of Debian. I had installed (and subsequenntly removed) the ATI fglrx driver; this had caused the problems. By re-installing libgl1-mesa-glx, I was able to experience the symptoms which lead to this bug report's creation. I had a hunch, though, that reinstalling some other package or packages would return my system to pre-fglrx (id est working) condition. I thus reintsalled all ef the xorg related packages:

libdmx-dev (1:1.0.2-2)
libdmx1 (1:1.0.2-2)
libfontenc-dev (1:1.0.4-2)
libfontenc1 (1:1.0.4-2)
libfs-dev (2:1.0.0-4)
libfs6 (2:1.0.0-4)
libgc1c2 (1:6.8-1)
libgl1-mesa-dev (6.5.3-1)
libgl1-mesa-dri ( 6.5.3-1)
libgl1-mesa-glx (6.5.3-1)
libgl1-mesa-glx-dbg (6.5.3-1)
libice-dev (1:1.0.3-2)
libice6 (1:1.0.3-2)
libnspr4-0d (4.6.6-3)
libsm-dev (2:1.0.3-1)
libsm6 (2:1.0.3-1)
libsynaptics0 (0.14.6c-1)
libx11-6 (2:1.1.2-1)
libx11-6-dbg (2:1.1.2-1)
libx11-data (2:1.1.2-1)
libx11-dev (2:1.1.2-1)
libx11-xcb-dev (2:1.1.2-1)
libx11-xcb1 (2:1.1.2-1)
libxau-dev (1:1.0.3-2)
libxau6 (1:1.0.3-2)
libxaw-headers (1: 1.0.3-3)
libxaw7 (1:1.0.3-3)
libxaw7-dev (1:1.0.3-3)
libxcomposite-dev (1:0.3.2-1)
libxcomposite1 (1:0.3.2-1)
libxdamage-dev (1:1.1.1-3)
libxdamage1 (1:1.1.1-3)
libxdmcp-dev (1:1.0.2-2)
libxdmcp6 (1: 1.0.2-2)
libxevie-dev (1:1.0.2-2)
libxevie1 (1:1.0.2-2)
libxext-dev (1:1.0.3-2)
libxext6 (1:1.0.3-2)
libxfixes-dev (1:4.0.3-2)
libxfixes3 (1:4.0.3-2)
libxfont-dev (1:1.2.8-1)
libxfont1 (1:1.2.8-1)
libxi-dev (2:1.1.0-2)
libxi6 (2:1.1.0-2)
libxinerama-dev (1:1.0.2-1)
libxinerama1 (1:1.0.2-1)
libxkbfile-dev (1:1.0.4-1)
libxkbfile1 (1:1.0.4-1)
libxkbui-dev (1:1.0.2-2)
libxkbui1 (1:1.0.2-2)
libxmu-dev (1: 1.0.3-1)
libxmu-headers (1:1.0.3-1)
libxmu6 (1:1.0.3-1)
libxmuu-dev (1:1.0.3-1)
libxmuu1 (1:1.0.3-1)
libxp6 (1:1.0.0.xsf1-1)
libxpm-dev (1:3.5.6-3)
libxpm4 (1:3.5.6-3)
libxrandr-dev (2:1.2.1-1)
libxrandr2 (2:1.2.1-1)
libxrender-dev (1:0.9.2-1)
libxrender1 (1:0.9.2-1)
libxres-dev (2:1.0.3-1)
libxres1 (2:1.0.3-1)
libxss-dev (1:1.1.2-1)
libxss1 (1:1.1.2-1)
libxt-dev (1:1.0.5-3)
libxt6 (1:1.0.5-3 )
libxtrap-dev (1:1.0.0-4)
libxtrap6 (1:1.0.0-4)
libxtst-dev (1:1.0.2-1)
libxtst6 (1:1.0.2-1)
libxv-dev (1:1.0.3-1)
libxv1 (1:1.0.3-1)
libxvmc-dev (1:1.0.4-2)
libxvmc1 (1:1.0.4-2)
libxxf86dga-dev (2: 1.0.1-2)
libxxf86dga1 (2:1.0.1-2)
libxxf86misc-dev (1:1.0.1-2)
libxxf86misc1 (1:1.0.1-2)
libxxf86vm-dev (1:1.0.1-2)
libxxf86vm1 (1:1.0.1-2)
mesa-utils (6.5.3-1)
x11proto-bigreqs-dev (1.0.2-4)
x11proto-composite-dev ( 0.3.1-2)
x11proto-core-dev (7.0.10-2)
x11proto-damage-dev (1.1.0-2)
x11proto-dmx-dev (2.2.2-4)
x11proto-evie-dev (1:1.0.2-4)
x11proto-fixes-dev (4.0-2)
x11proto-fontcache-dev (0.1.2-4)
x11proto-fonts-dev ( 2.0.2-5)
x11proto-gl-dev (1.4.8-1)
x11proto-input-dev (1.4.2-1)
x11proto-kb-dev (1.0.3-2)
x11proto-randr-dev (1.2.1-2)
x11proto-record-dev (1.13.2-4)
x11proto-render-dev (2:0.9.2-4)
x11proto-resource-dev ( 1.0.2-4)
x11proto-scrnsaver-dev (1.1.0.0-1)
x11proto-trap-dev (3.4.3-5)
x11proto-video-dev (2.2.2-4)
x11proto-xcmisc-dev (1.1.2-4)
x11proto-xext-dev (7.0.2-5)
x11proto-xf86bigfont-dev (1.1.2-4)
x11proto-xf86dga-dev ( 2.0.2-4)
x11proto-xf86dri-dev (2.0.3-4)
x11proto-xf86misc-dev (0.9.2-4)
x11proto-xf86vidmode-dev (2.2.2-4)
x11proto-xinerama-dev (1.1.2-4)
xorg (1:7.2-3)
xorg-dev (1:7.2-3)
xorg-docs (1:1.4-2)
xserver-xorg (1: 7.2-3)
xserver-xorg-core (2:1.3.0.0.dfsg-6)
xserver-xorg-core-dbg (2:1.3.0.0.dfsg-6)
xserver-xorg-dev (2:1.3.0.0.dfsg-6)
xserver-xorg-input-evdev (1:1.1.5-2)
xserver-xorg-input-kbd (1:1.1.1-1)
xserver-xorg-input-mouse (1: 1.1.2-1)
xserver-xorg-input-synaptics (0.14.7~git20070517-2)
xserver-xorg-video-ati (1:6.6.192-1)
xtrans-dev (1.0.3-2)

This has resulted in the negation of the symptoms.

Please let me know if this is sufficiently sattisfactory that the bug may be closed -- or if more information is wanted.

Cheers.