What Is This?

I went to my home page to check some things and something strange happened. After a few seconds all the pages greyed out and I couldn’t click any links. But not the whole page, only the top part. I can scroll down and everything looks normal. This happens only with my computer, only with firefox, and only my home page. The same pages on my computer works fine but not the ones I have uploaded. What could it be? I have restarted firefox but that didn’t help.

http://www.highrankings.com/forum/index.php?act=attach&type=post&id=877