I upgraded to Snow Leopard, ran into tons of problems, and decided to revert back. I made a disc image of my hard drive, then wiped it and reinstalled Leopard. Now I can't find my FileMaker 9 Advanced serial number, so I'm wondering what I need to pull over from the image to get it working again? I copied over everything I found in the user/preferences folder, but I must have missed something...FileMaker keeps saying file it needs to run are missing or damaged.

Can someone point me in the right direction here?

I doubt its as easy as copying a preference file. Otherwise, Filemaker would have trouble with software piracy. If you can find some sort of proof of purchase you might be able to plead your case with Filemaker support and have them email you your license key.

Re-wipe and re-install from the disc image first.

Run FMPro, then FileMaker Pro > About FileMaker Pro > Info

Your serial number will then be displayed.

Well, I got it going. I found my serial number in some paperwork, but then I discovered the joy of FileMaker's activation process. Apparently just having a serial number isn't good enough anymore, so FileMaker started using an online activation process similar to what QuarkXPress uses. This means if you have to move it from one to computer to another, you have to call them and beg for forgiveness since they show it's installed on another computer.

Lesson learned #1...deactivate before wiping your hard drive! Lesson learned #2...snow leopard is a painful upgrade.