After further investigation I've found that after the second login Xgl is way too slow to start and gnome-session starts _before_ Xgl (in Xgl-session Xgl is started in the background)
A workaround is to add a "sleep 5" in /usr/share/xserver-xgl/Xgl-session after the line "$XGL_WRAPPER $XGL_DISPLAY $XGL_ACCEL_OPTS $XGL_OPTS &"
Now I've to find out why Xgl is so slow on second startup and next.
The other message in .xsession-error are just GTK warnings and doesn't affect session startup.
Well it's a little bit weird.
After further investigation I've found that after the second login Xgl is way too slow to start and gnome-session starts _before_ Xgl (in Xgl-session Xgl is started in the background)
A workaround is to add a "sleep 5" in /usr/share/ xserver- xgl/Xgl- session after the line "$XGL_WRAPPER $XGL_DISPLAY $XGL_ACCEL_OPTS $XGL_OPTS &"
Now I've to find out why Xgl is so slow on second startup and next.
The other message in .xsession-error are just GTK warnings and doesn't affect session startup.