OK, sent my player to sony, they are exchanging it for a new one, there must be a bad batch of Nh 900's out there. i bought mine from pricesrite.com. soooooooooooooooooo.. use your best judgement.
I have the exact same problem.
I have 2 computers at my house (with service pack 1)
and it crashes at nearly the identical point yours does.
is this a faulty player? everything else about it works fine