My iPod Touch 4G got stuck while syncing with iTunes on a Mac Mini. I canceled the sync using the slider on the iPod but "Canceling sync" remained on the screen. I was able to open some apps, but Music would not launch. I tried to restart the iPod and now it just shows the Apple logo and is stuck on a progress bar. It cannot be rebooted.

Now it only connects with iPhoto, it is possible to import images. But when connecting to iTunes the progress bar is turning around and no content appears.

Is there a way to fix this? Thank you for your help.