From your message, should I surmise that this was an upgrade installation rather than a clean installation? I'm wondering if something got broken in the process. If this was an upgrade install, what version of OE6 did you have BEFORE the OS upgrade install as opposed to AFTER the upgrade? Is this the RTM, RC2, or RC1 of WinXP? I'm wondering if it's possible that you installed an earlier version of OE6 over a later version of OE6, in other words.
If this was a clean install, I can't think what would cause this issue. I've got a bunch of clean WinXP installs in this room, and none of them has the problem you're reporting.
Are you seeing any other GUI glitches?
Regards,
Jim