explorer illegal operation shut down

[drexel5]

I am quite new to Limewire and had no problems with it for about a week. Now, after I shut it down I seem to get a message stating explorer has made an illegal operation and will be shut down. It doesn't quite shutdown, but removes half my icons from my sys tray and causes me to re-boot. I also noticed that when I disconnect and shut Limewire down that my firewall tells me it is still listening to 3 different ports. My web browsing seems a bit slower too. Can anyone shed any light on this matter, please?

My specs are:
win 98se, (fully updated)
1.8ghz processor
512mb ram
40gb hdd, (with plenty of space)
cable 1mb broadband connection (ntl)

I also have zone alarm basic firewall, Norton antivirus 2003 (systemworks edition), ad-aware se personal, spybot s+d, winpatrol. All are fully up to date and are ran regularly.