I'm pleased to hear your thoughtful comments even if I'm not certain we really helped resolve your problem as much as you did so on your own by finding that location that seems to prevent it from occurring. Thank you very much.
Based on your post, I will request that this thread be marked solved.
Even though you've found a solution that currently works, I would still consider the option I presented as a fallback position in case things don't remain as they are at the moment - then you can recover the desktop with two clicks instead of resetting it completely - but that's entirely up to you.
And welcome to Vista Forums! Now that you know where we are, bookmark the site and post anytime you have further questions or problems or if you just want to browse and learn (especially the Tutorial section offers some excellent advice on a wide variety of topics) or even if you want to try to help answer a question if you happen to see one where you know the answer and it hasn't already been posted. While it most likely won't be us the next time (though it might), there are many very skilled, experienced, knowledgeable, and friendly people here who, like us, volunteer their time to help others and one or maybe even several will respond to your post to assist you. While there are other forums on the web that do this sort of thing, you've now found what I think is the best (and I've posted in and/or checked out quite a few) so don't lose this link - you never know when it might come in handy again.
Good luck and best wishes.