Hi mate,
My advise to you is take it back to where you purchased it, provided you've not opened up the system and voided yr warranty. After all its only a couple of months old. Downgrade it to 1.5 then add official firmware from a umd title use a newish game. They will be none the wiser, explain it does'nt boot up right. Should give you a replacement!!! This is only relevent of course if you bought it retail and have kept yr till receipt.

Good luck. Chris