While quite a number of the iPhone users has got some errors during the iPhone 2.0.1 firmware upgrade, you might want to disable the Airplane mode before you do the upgrading.

If you see the following error, you can disable the Airplane mode when you are on the emergency screen

“Information for activation cannot be obtained from the iPhone”

if you see the the error below, you can click Restore in iTunes to fix it

“iTunes could not update the carrier settings on your iPhone. An unknown error occurred (OxE80000001).”

Source [iPhoneBuzz]