unable to sync iphone 4 to itunes

Any change after restarting your computer?

Interestingly, the solution was that if you purchase apps on another device (such as an ipad as is the case here) the second device must first be sync'd with your mac computer. So after I sync the ipad (which some apps were purchased from) to the imac I was able to sync my iphone. Problem solved. This has never been an issue in the past but now it seem to be. Could be a bug with the new OS. ??

Before you can transfer apps from your iTunes library on your computer to another device, the apps need to be in your iTunes library. This has been the same since day one in regards to apps, music, and anything else downloaded direct with one device when wanting to transfer the same content to another device. There is an automatic downloads option for music, books, and apps with iTunes on your computer and with each iOS device. Download an app with one iOS device and the app will be downloaded by iTunes on your computer and with the other iOS device automatically and vice-versa.