A few users have reported an issue in which the iPad does not show up under the “My Devices” list in iTunes 9.1.
If you are experiencing this issue, try switching the iPad to a different USB report or turning the iPad off then back on again.
Also, try leaving your iPad connected to your Mac or PC, then restarting the Mac or PC while the iPad is still connected.
Failing the aforementioned, the issue can be resolved via a simple two-step process:
- Uninstall iTunes per Apple’s instructions (look under “Completely Remove iTunes from Mac OS X”)
- Reinstall iTunes (download here)