A client’s database suddenly was showing blank entries in dropdown selection boxes (combo boxes), on forms, reports, and even the datasheet. The data was there, and the combo boxes actually have items and attached values, just no display. After futzing for a while and googling away, finally discovered that this is a “known issue” with Microsoft Office 2003 Service Pack 3. One more reason to be shy about service packs, especially the kind that automatically update. Surprise!
The solution was to remove the “Format” property for the fields in the combo box. An alterative, from Microsoft, is to use the SQL query for the combo box to append a blank string to the string value (thus ignoring the Access field Format property).
KB945280 — Combo box controls and list box controls display no value or incorrect values in Access 2003 after you install Office 2003 Service Pack 3
Microsoft also issued a hot-fix for Access issues post SP3, which I haven’t tried yet, but it’s supposed to fix this problem.
KB945674 — Description of the Access 2003 post-Service Pack 3 hotfix package: December 18, 2007
C’est la vie.