I too have been having these same problems lately, when it freezes up I have to end up logging off, and the fatal exception loses the server anyway. The fatal exception sometimes was happening many times a day, sometimes after only a minute or two on line, always to do with outlook Express.
After consulting with my ISP, AOL, I have removed Outlook Express from my computer altogether, don't need it with AOL, now (touch wood) everything seems fine.
Just a suggestion, depending what ISP you are with, you might be able to do the same?
Regards,
"lame"