Yet others who use the same version and OS are not reporting the same problem. Thus some investigation is needed to rule out other possible causes:
When you say that "I have it with all of my FileMaker databases" can you confirm that more than one of these files were not created initially as a copy of one of your existing files and you did not copy nor import items from one of your other files?" (If damage to the file is an issue, you may copy that problem along with the othe features/data you are copying or importing.)
It may be hard to be sure. You may need to create a small database file from scratch and see if it exhibits this crash behavior.
Have you run any utitilites to confirm that your computer and it's hardware are functioning normally. I don't have Windows 7 myself yet, but XP has the venerable "checkDisk" utility to run to check for issues. Have you tried checking your system out with such a utility?
Have you tried working with these files on another computer to see if that makes a difference? (And yes I fully understand that you may not have access to such a computer, but if you can, it can help confirm/rule out possible causes here.)
When you export your data, do you always export to the same director,y or always using the the same user account?