Border not showing up for me in Firefox

[JIK1987]

Today, out of nowhere, certain parts of tables stopped working. Depending on the style, the bottom border will be missing, or the top, or even the side of some tables. I don't know how or why this could have happened, and it doesn't make sense that some would do it and others wouldn't (they are all a child of one style). In Internet Explorer, they work. And for at least one other person, it works for them in FF. It may just be me, but they did work this morning, and if I'm seeing no borders, i am sure other people will too.

I just don't know if it is just me, because I do see the borders temporarily for half a second and then they disappear, and the bottom of the quick reply appears when I hover over a the vbcodes.

Any ideas? I've restarted my computer and cleared my cookies (in case it is just me, but nothing changed).