WIFI Sync with iPhone 5

Hello - I used WIFI sync with my iMac and the iPhone 4S without any problems for a longer time. Since upgrading to iOS 6 and the change to iPhone 5 I have serious problems with the WIFI sync. The iPhone will not be recognized in iTunes (10.7), I have to restart iTunes for getting it recognized, the sync is slow and usually stops if music must be transferred. iTunes hangs then often and must be forced quit. The syncing via USB cable works fine. I find similar problems with my iPad 3rd gen.