Thank you for your post.
It's difficult to determine the cause based on what you said, but there are a couple of things I would like to test...
First, you mention that you are usually "working with a specific database". In case the database file is causing this problem, I'd like to attempt a Recover. That is, once you are able to launch FileMaker Pro, pull down the File menu and select Recover. Select the file that may be causing the problem. FileMaker Pro will then create a new file and attempt to clean up any discrepancies within the file. When finished, open the Recovered file, and see if you are able to make FileMaker Pro crash.
Next, create a new user account. Log in to that user account and launch FileMaker Pro. This creates a new Preferences file for the current user. Does this launch successfully? If so, then remove the Preferences file from your original user account. This can be found at:
User Account -> Library -> Preferences -> com.filemaker.*
(I have several versions of FileMaker Pro on my machine, that I'm unsure of the exact filename).
Launch FileMaker again, and a new Preferences file will be created. Does this work?
If this also fails, then run Disk Utility, select the hard disk, and click "Repair disk permissions". You can find Disk Utility at:
Hard Disk -> Applications -> Utilities -> Disk Utility
Keep me updated with any progress.
From the initial post, this is occurring on a Snow Leopard system. Perhaps there's a font issue involved. That could be with a font used in one file and not in another so this could show as file specific even though the file is not damaged.
Any recommendations on how to chase down a font issue?
I'm not a Mac user at the moment so I'm only reporting from what I've seen in this forum. You might check out Apple's support site and search under Snow Leopard and Font to see what you can pull up.