[Chimera-users] problem with chimera

Hello all, I have been using chimera and dock6.0 on a RHL9.0 system. More recently if i perform simple processes like coloring a molecule in chimera, the display goes blank and also logs me out of the session. meaning, i come back to the graphical login for my system. I am unable to proceed any further as repeated attempts to do simple tasks simply logs me out. Kindly help with suggestions. With regards, Vinay.