Spent the morning debugging it on my NVIDIA 7050 MCP. It looks like there is a bug inside nvidia-dirvers-275.xx.xx which causes the segfault. Fix/workaround is to drop Option "UseEvents" line from xorg.conf. As written here: http://forum.sabayon.org/viewtopic.php?f=86&t=24532&p=137185#p137185
-- Fabio Erculiani
