Well, I had... in fact, I just had that problem this week, when the iTunes updated to 10.3... As I said, I'm not sure exactly why this happens with my windows, since many people don't seem to have that problem, but I believe there's something to do with my gadgets (I have gadgets that are related to iTunes), but even when I uninstall the gadgets and tried the normal methods to duplicate iTunes, I couldn't fix it.
Since I've been having consistent problems with that for quite a while (about 1,5 year, now) and always tried different methods which, sometimes did the trick, sometimes, it didn't. I always looked for a method that would be guaranteed. And this is what I've come up with.
Either way, I'm sure there might be other ways to do it, but it's always nice to share our experiences so people have as many options as they can when it comes to fixing a problem.