Or, you could avoid a hard reset by just going into the extended_ROM folder and running specifically the necessary .cabs, as listed by Colonel in his "Official List of Necessary ExtRom Cabs For Each Carrier" topic.
http://www.ppcgeeks.com/official-lis...ier-t4189.html He even provides a link to download the necessary .cabs so that you don't even have to figure out how to get into your extended_ROM.