I've also found over the years that in dbs with complex forms &/or reports (with VBA code), Access sometimes fails to compile properly, eg, it doesn't recognise basic things like 'Me' in code.
The 'fix' seems to be to decompile the code, and then recompile it, followed by a Repair/Compact. To decompile, run this from the command line (or a shortcut you set up), like this:
[PathToAccess] [PathTpMDB] /decompile
HTH
Max Hugen
Australia