I use IE5.5 and have the same problem. I even set my own internet options to never check for new pages and it still does the same thing. Most frustrating is it refreshes whenever I make a post. So I strted just looking at the times of the postings to see if there is anything new and pretty much ignore the lightbulbs for now. It's a little more hassle but it works.

Maybe it's a flaw in IE5.5 as I don't remember this problem with previous versions.