I think you're correct regarding the db being corrupted, I've had a lot of other issues that are very odd.
Sometimes running a "Compact & Repair" will fix it, but I find most often that does not work for me.

If you open up a brand new blank database, go to Import, select Access Database, you can select all the Objects (Tables, Queries, Macros, etc) from the bad/corrupt database and import it into the new one. If you want your Export Specifications to move over too, be sure to click on the Options tab and select the "Import/Export Specs" option.

Doing this should create a brand new uncorrupted copy of your database.