Fatal server error: [ 90638.275] Caught signal 11 (Segmentation fault). Server aborting [ 90638.275] [ 90638.276] After that there is constant flood of messages from 'EQ overflow continuing'This is essentially the same backtrace that you already reported in #686474, sorry for not having followed up on that. It seems that this is triggered by enabling the "GLXVBlank" option in xorg.conf, and that there is a fix in version 1.0.3¹. I'll see to include this in the Debian package.
OK, I'll disable it and try to play for some time to see if problems stops.