iPhone 4S: Update and restore issues double whammy

While trying to update to iOS 5.1 on an older Mac running Leopard and iTunes 10.5 away from home, the update was downloaded, but couldn't be installed. The error message said it was due to older operating system. The phone is frozen at the "USB to iTunes" screen, and hard reset isn't working. It occasionally goes to the apple-on-black start up screen, then back to iTunes screen.

Back at home with a Mac running Lion 10.7.3, iTunes 10.6, iOS 5.01. Now the phone isn't recognized in iTunes. I've restarted iTunes and Mac. I have the phone charging.

Forget the update, I'd just like to restore at this point! Thanks!