If you are getting a strange error about collation sequence in Access 2010 when closing a .mdb file,
Something like “Selected collating sequence not supported with the specified file format”.
When you look this up you will find advice to set the collating sequence to general. However this will not work. And in some cases the database will become corrupt.
The most likely cause is a recent Service Pack to Access, SP1. The latest Service Pak of Access 2010 appears to have a bug in the compact on close feature. The cure is to turn this off.