Interesting! Now, I don't claim to be a real guru, but I will offer the following thought as a start; excuse me if this is a granny/eggs answer.
Do the Ctrl/Alt/Del routine to see what Applications and TSRs are running in the background. Disable the less important ones one-at-a-time and go back to your work each time and see if the problem disappears.
By less important I mean printer managers, Textbridge Instant Access Program, Virus Protection and Firewall (But only if Off-Line!!) etc.
If you get down to Explorer and Systray (the minimum 98SE must have) and starting IE/OE still causes the problem, then you probably have a Windows *.DLL mismatch caused when you installed a third-party program that over-wrote the original Windows version.
Check by looking at the dates of the Windows files; they should all be the same or similar. A glaring difference will suggest that getting an original version of the offending DLL or SYS file might fix the problem.
Otherwise, re-install Windows! Yuk.
[ 08 August 2001: Message edited by: fobotcso ]