Hello trisk. As you suggested I did gnome-appearance-properties in the xterm using failsafe session in GDM.
I got the desktop settings window where I could adjust visual effects. I reset the settings as default. But when I exit this session and log on to the GDM desktop, it again opens with the advanced visual effects and hangs immediately! Any ways thanks a lot for the suggestion. Do you have any other guess? I am nearly out of patience now.. thinking of formating and reinstalling. Please can any one report this problem to any core team member? There must be a way out... Thanks. Jay Mahadeokar. This message posted from opensolaris.org