Had an unusual problem with my iPhone this week. Windows Vista wouldn't see it as a mobile device anymore. It still syncs and is seen by iTunes. No issue there. I just couldn't see my iPhone in "My Computer" any more. I dug around the net trying to find a solution. I uninstalled and reinstalled iTunes and associated software. That's didn't fix it. I finally found a clue in a thread on Apple support discussion board. The issue: MMS photos. I went in a cleared out my chat history including any photos that were MMS'ed to me. Guess what? Windows Vista now sees my iPhone again. How dumb is that!

Issue On: Windows Vista SP2 / iTunes 9.0.2.25 / iPhone OS 3.1.2