I've noticed it, but never paid much attention to the "P" I get when I turn the unit on until reading this from the V site:
"If the unit has been changed, P will appear briefly in the Bogey Counter soon after V1 is switched on (after the lamps-on test, but before the Mode indicator appears.) "
I've not made any changes at all to the programing. (ver 3.872, sn 014)
I bought it directly from V and have just emailed them.