Nokia 7160 shows "field test mode" when plugged in through serial cable to computer

Subject pretty much says it all.
Can anyone tell me what the problem is, and/or if there is a way to
solve it? Just a reflash of the firmware?

Cingular csr told me that this is indicative of "water damage", which
I have heard these phones are predisposed to. If this is in an FAQ
somewhere, please point the way. Didnt see one on the way in!

Thanks

jeff

p.s. Haven't tried using IR. Should I expect the same results. Its a
pain to get to an ir enabled comp around here :-(