I noticed something a few days ago but never paid it much attention. I think that when you select Quick Links on the menu bar up there while in the forums, as soon as you hover over active topics and under it somehow adds an extra space of code that makes the border line below "Who's Online" disappear. Nothing extraordinary but I was just curious as to whether anyone else noticed ?
I guess it would depend on what browser and OS you're using also. I am on IE 6 +something on windows 2kNT pro.... I sometimes use FF but I'm not sure if it does it on that yet.
Odd... I ran some tests and IE 6.x for Windows/XP has no bug on my end as you mentioned, on either forum skin. Firefox for Windows/XP (as well as on Mac OS X) shows no bug. Safari (Mac OS X) also shows no bug. Can anyone see that bug on Opera at all, or see it on Internet Explorer's Win2k iteration?
What resolution are you running, MJ? If you have Win2k Pro, use 1024x768 with IE and be sure you're viewing a thread or something and then select it. If it doesn't happen then, it is most probably a local, not global, issue.