http://packages.debian.org/changelog....6-2/changelogOne possible solution is to roll back the GLX 1.4 enablement patches, and the patch which caused the memory leak to appear. These GLX patches were produced by RedHat and incorporated into Debian, they were not brought in due to Ubuntu-specific requirements and thus it is believed dropping these patches would not impact any of Lucid's development goals. The one risk to be mindful of is if any userspace applications have come to depend on the newer GLX functionality.
I hope this answers your question.xorg-server (2:188.8.131.521-1) experimental; urgency=low
[ Julien Cristau ]
* Enable GLX 1.4 on DRI2 and swrast (from upstream, via F12).