Once you rename the back-end, you need to relink the front-end.
You can use the Linked Table Manager (under Tools | Add-ins in Access 97,
and under Tools | Database Utilities in Access 2003: sorry, but I can't
remember which of those two locations it's in in the other versions), or you
can use VBA code such as what's at http://www.mvps.org/access/tables/tbl0009.htm at "The Access Web"