As far as I know, yes, you change type, but then I don't allow that spell, so I'm far from an expert.
That said, I'm itching to play a Psion PC for once (which I've never used, not even a bit of, and know the rules only from what I'd seen used against me, which is gishes and a blaster). Care to post your build so I can study it?
Am I better off with a Magic Transparent (Mantle) Spell-to-Power Erudite, or do I otherwise combine the 2 to godly power?