Earlier this week I ran into the problem
several others have been reporting: the inability to open certain Excel files after the Office 2004 v11.6.1 updater has been applied. Both older Mac as well as all Windows versions can still open the affected files, but reverting (reinstalling and updating) Office is a hassle.
Those who haven't yet updated their MS Office 2004 with the latest security updater 11.6.1 (100907) may want to
wait until Microsoft has addressed this bug. Right now MS Autoupdate doesn't list the updater any longer, but the standalone version (Office2004-1161UpdateEN.dmg) may still be around.
