Bebu, I'm having daily conversations with the McAfee people! They don't have a clue to my issues.

Three general ideas:

Java update. A must.
Clear your cache. The chat server requires a lot of memory and if you have loads of pictures, for instance from visiting the gallery, you may not have enough memory to load chat.

In the same vein, change your computer's allotment for memory. Increase it above the default setting.