I've got an NXT that 'forgets' its firmware; when I downloaded the firmware, it worked fine.
I removed the batteries (needed them for another NXT)
Then, the next day, when I turn it on, it maded that hissing-ticking sound indicating it is waiting for a firmware download.
It worked fine again when I downloaded again. (the LEGO 1.31 version).
I turned it off normally, and turn it back on, it still worked.
Then I left it on, to test what happens if I leave it to 'fall asleep'. When I returned, (30 minutes later, sleep time was set to 5), it was hissing, but not ticking. So I pushed the reset button, and tried to download again, but that failed.
The first 2 steps (finding NXT, preparing NXT) go fine, the third step fails: communication error (as if it was disconnected)
Error code: -1073807339
Does anyone have a clue what's going on? Or, even better, what to do about it?