I don't know what's causing this and it happens about 50% of the time. When I connect my iPhone (3G 16gb) to iTunes it says that it is installing all of the apps that I have had installed on my phone since day one....after about 10 minutes of "installing" and syncing it says that I have 15 errors and my apps were not installed(I currently have 15 apps). Looking at my phone, all the icons still exist and most still work but 1 or 2 (different apps each time) do not work, when the icon is tapped a popup window comes up that says something like this application cannot be opened. I have to remove the apps that don't work from both iTunes and the iPhone and then redownload and resync for them to work. (not difficult but frustrating especially when it is an app that keeps records like WeightTrack and I lose data) FYI - Using windows XP, iTunes 7.7, has happened with both apps that I purchased through iTunes and iPhone. Anyone else have this issue? what am I doing wrong?