Hopefully you have this fixed by now.....
I had this happen the other day. I had it hooked to my computer with the SD card mounted. I disconnected the phone from the computer without unmounting the SD card first. The phone started scanning and didn't stop, just as you were reporting. To get it working again I reconnected it and remounted the SD card. It took a little longer than usual to mount but it eventually worked. I unmounted before disconnecting it after that and all was well. I typically disconnect without unmounting and have not seen this again, seems like a fluke.