Yesterday I've got my #11. At the begining I thought it was broken, as it didn't record any video nor shot any pics. However my 8GB SDHC Class4 card was working OK in PC-mode. My card was taken from Nokia 5800 XM, probably factory formatted by Nokia. Reformatting under Windows (Quick Format) had no effect. Later I tried an old 2gb card, and... whoa! It worked! So I knew it's not the keychain problem, ufff...
Then I tried SD Formatter. It formatted my card and now everything works!
I think it is a good idea to add this info to FAQ, because I couldn't find the solution here.