I think I may have a virus on my computer. Firefox has been acting very wacky for the last two days. For a while it wouldn't respond at all when I clicked its icon in the system tray. Then I started getting this dialog when doing my online banking at chase.com. Specifically, clicking the date calendar icon in the Pay Bills section. Other sites seem unaffected.

A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.

Script: chrome://tavgp/content/libs/include.js:595

This started when I followed a prompt and installed the latest version of Firefox, so maybe it's FF itself and not a virus. I have uninstalled FF and reinstalled it and the same behavior continues. No other programs seem affected. I ran a virus scan (AVG) and it didn't find any problems.

Any ideas?