how to repair corrupt Filemaker Pro database?

Hi, I'm on Mac OS 10.6.8, using Filemaker Pro 8.0v1

My database has gradually gotten messed up in recent months:

importing data from outside sources thru Excel often causes it to crash;
entering data in certain fields of many records causes it to crash;
and as of yesterday, creating any new record in the DB causes it to crash.

Is there any way to clean/repair/restore this database without losing any of my data?
Or can I create a new clean DB, and import all my existing data into it without bringing the same problems along?

Please help. I'm kinda screwed.

thanks,
Josh