I doubt this is specific to this handset, but I'm using a P500. It has only a little memory space, so I was removing apps and data I don't use. I must have accidentally removed something I shouldn't, because now it just constantly keeps popping up with: Sorry! The process com.android.phone has stopped unexpectedly. Please try again. Force close and Sorry! The application Messaging (process com.android.mms) has stopped unexpectedly. Please try again. Force close and these two messages just keep repeating over and over again. And the signal indicator keeps flipping between full strength and no-signal, and a notification indicator icon indicating "SIM has been removed" pops up then disappears, over and over. Android v2.2 Power cycled, pulled battery out, tried without SIM and SD, just keeps doing it. The handset was bought elsewhere and then used on this network, so it is not network-supplied, meaning no OS updates from the network. Like with Windows, can you run a "repair" that will replace missing / corrupt system files? Or do I need to lose everything and reformat it? Is there a built-in way to reload factory settings or do I need to download it to a PC and flash it? Thanks, Jono.