I'm selling my 6600 and today I was trying to reset all the information but every now and then its asking me for the lock code. I don't remember setting one, but the default 12345 doesn't work.

Is there anyway to reset it? Would the buyer have to take it into a shop and get it flashed? (Might be a good idea anyway, the firmware is quite old)

Take it to a Nokia service centre and say its freezing up......

If its still under warranty there will be no charge.