guess what, I just spoke with Plextor tech support to make sure if I did that I wouldn't void any warranty and they said *unofficially* it was ok.
So I guess I'll be filing for the rest of the evening.
ok, so I just installed the drive, but it doesn't fit! The tray is too high for the door cover by about 2mm because of the curved corner shape of the slot, so it won't eject. I tried it in both upper and lower bays, but both the same. Damn!?!!