Access 2003, Forgetting selection checkboxes upon closing document

We're using Access 2003 professionally and we have databases with checkboxes
in them, through which we export selected fields to Excel.
However, for some reason, Acess stores the names of the boxes you check and
keeps them there forever unless you uncheck them again manually. Naturally,
this is not very practical when it comes to unchecking say 1000 checkboxes.
How can I make Access to stop remembering which checkboxes were checked the
last time we opened the Access document/database?