On Windows Vista, everything works through the USB ports except IOS devices. This just started and I can't get things to work. Help!

The past few days I find my IOS devices don't show up in "My Computer" and they don't show up in iTunes. All other USB devices work well. I am using Windows Vista. I have tried several troubleshooting things, including unintalling and reinstalling iTunes, stopping and starting the Apple monitors, etc. Nothing is working. Ideas?