Ok, I think I'm getting closer.
Now it says missing operating system.
Sorry to resurrect what's getting to be an old thread, but I have something of an update.
Ran into this problem recently and have a solution that's better if you don't want windows on the optibay drive.
Some background: I have a 2.33ghz 2006 first gen core 2 duo MBP. I have an SSD as the main drive and a larger drive in the optical bay using one of the cheap chinese optibay SATA-->PATA optibay adapter.
I upgraded to a bigger SSD recently and when I went to install windows 7 on the second partition I created on the SSD a couple days ago I ran into some.. problems. I wanted windows on the SSD because it, on SATA, is *far* faster than the spinning disk on PATA.
With the optibay pulled I installed windows on the SSD.
I discovered that with my optibay HD in I got the error described above "missing operating system" and with it out windows booted just fine.
I wondered if the partition table on the optibay drive might be throwing EFI off, as it sees the PATA bus first, so I pulled the data off the drive, reformatted it as MBR instead of GPT, and dropped my data back on.
Voila, it works! Windows on the SSD boots fine!
(also, I suspect, though I never bothered to test it since the above method works, that tossing grub or another boot loader on the optibay drive and pointing it at the windows install would also solve this problem)