I think the main answer for your rephrased question will be "Google It".

Hmmm, I had used compatibility mode on a different site and tab, but maybe that one was being affected.

@Simon, I'm tired of the Firefox bugs that they won't fix, and Chrome had something wrong that escapes me right now.

@nhinkle, I have a 27" screen, maxed out, so then I zoom in, looks pretty normal when using it. I just did the cache flush, restarted the browser and the problem fixed itself. Guess it will be status-norepro, but of course if it can happen once, it'll happen again.

@random, no, I hate that as much as I hate rebooting the computer to fix problems, but now that I've reported it, I'll do that. Note, it isn't happening on the other sites.