First, I'm assuming that you're doing this on a Form. If so:
Make sure you're doing this in the correct "view" ... the new Layout view doesn't fire code
If you're sure of that, make sure the db is in a Trusted Location or that Macros have been enabled (you'll be notified of this on opening the db).
You might try a Compact & Repair operation. Click the Office button - Manage and try C&R.
If that doesn't work, importing to a new, blank database could help. '
Make a backup before trying any of these.
