If iTunes says: "iPhone or iPod detected but not recognized " then...
...eject any CDs or DVDs from your drive(s), disconnect your device, close iTunes, then reconnect your device. It should work now.
After I provisioned my Touch on the Mac, all of a sudden it stopped connecting to iTunes in Windows, where I have my music library and the device's backup files.
After a lot of googling I found this trick mentioned somewhere, and as silly as it sounds, it fixed my problem
