I just got a refurbed 2500xp from Newegg. I put it in my box and fired it up. I have all the multipliers unlocked. I checked the code on the chip, and it was made in week 47 of 03. I thought this was supposed to be locked. Not that I'm complaining.
The multipliers appear open on any locked chip, you should not have posted this thread before you actually tried booting with a changed multiplier. Asshat.