Ugh, just buy the OEM part next time.

What made you decide the DSLR was worth the extra work in the end? That's a serious time commitment, so you must have seen some benefit over just waiting.

Check if the adapter's master/slave jumper is set right, those old Macs can be picky about that. I've seen machines act dead just because the drive wasn't set as master. Also, some CF cards have weird timing issues that IDE drives didn't, so a different brand might not work even if yours did.

Was it really that big a deal though?

Two hundred bucks for a cast copy is brutal. I've heard VCoins is a good marketplace where dealers have their reputations on the line.