Finally, there seems to be an end to my gyach story. with the help of sridhar, i found out how to avoid crashes, and that its coz of those animated smilies! doh!. Now everything is back to normal, and that i now have the ability to see who are invisible and those who are really offline.
To solve the problem, you have to disable the smilies, using OPTIONS window. Thats it. things back to normal