One possibility is that on the 'error' computer, Access has a missing
reference.
Open a code module, click Tools | References, and look for a "MISSING"
prefix on one of the checked references.
If found, uncheck it, note it down, and close/save (you may not be able to
uncheck it, depending on which reference it is). Close Access, re-open it,
go back to references and re-check the formerly-missing reference, and
close/save.
