Looks like a JTAG fix is required here
Quite a few are having problems with SD Cards,personally I would have Formatted the card 1st and checked it in windows before going anywhere near my GP2X.
Did you use a mains adapter ?
ALWAYS use a good mains adapter (or new Alkalines) when updating...
Just Upgraded firmware from 1.2.1 to 1.4.0.No problem using Dane-Lec 512Mb card.
Using a Mains adaptor from Argos
Think the main problem with upgrading firmware is that you should use an adaptor as mentioned elsewhere rechargables can only provide 2.4v this may not be enough voltage to flash the...