Ok, so I have the install.us app (not sure if its allowed to be spoken about on here) and have apps that I have downloaded from it. But up until now, nothing has ever gone... differently, all the apps that were downloaded through the app, synced but everything was fine. And just, the last time I synced my iPod touch with iTunes to says I needed to Authorize my iTunes with this iPod otherwise an app would be deleted. So I authorized and then it asked me again which I only have 2 authorisations left. Does anyone know why this has done this... I have the latest version of said app, and running 3.1.2 FW on 2G iPod Touch EDIT: I think I know the reason, my iPod Touch is 3.1.2 FW and the latest version of that app requires iOS 3.1.3 or later.