weird behavior with Outlook Express

Hello All;
I’ve notice some really weird behavior with Outlook Express and was wondering if anyone else had the same experience. The problem happens when I click on New Mail and begin writing an e-mail: sometimes the text that I’m writing will appear to disintegrate (kind of hard to describe - it looks like when you write something in pencil and then do a lousy job erasing it, leaving behind bits of what you wrote). My computer then completely locks up and I have to do a hard reboot. I considered a virus and scanned my entire system with Norton Anti-Virus with the latest definitions (Oct 30) and it came up empty. I’ve tried to recreate the problem but as luck would have it this happens only randomly, so I’m not sure what I’m doing to trigger this. I should also mention that the problem occurs whether or not I’m connected (I use a phone line and modem). I’m running Windows98SE and Outlook Express version 5.00.2919.6600. Any ideas or suggestions would be very much appreciated.

Thanks as always to those who take the time to respond.
Best wishes,
smeghead