Originally Posted by MmavisO
Unplugged battery for a couple of min, put most recent PB FW on card (I always take off all other versions--only one at a time, and nothing else on the card at all). No change. Boots up to 20110115, and freezes. No LOST dir created, which is a first for me--every time I've updated in the past, I get a LOST dir on the card. But not any more. Not with yesterday's (I did yesterday), not today's, and not with the PB (I did when I first installed it).
Unplug battery to shutdown the device, press and hold "Vol+" while pressing and holding "Power On". Release the buttons once the boot logo shows up. If the flash process aborts you just may just have a damaged filesystem on your external SD card.