I had the same issue with my son's iPod touch and I agree that the battery draining could cause it (seems to be the case here).
I tried the various apps that were supposed iPhone browsers, through which I was supposed to be able to remove lock - no go.
I also attached to my Windows computer and launched iTunes, in which it kept giving me a message that it couldn't connect (forget exact message, but it actually isn't important here.
What *did* work was I went to my Mac (important? don't know) and logged on as a user that didn't use iTunes and launched iTunes for very first time (with iPod already attached). I was able to synch the iPod and when I looked at it, it was no longer disabled.