Is the "event field" the event column in the property sheet? You get no warnings or messages about not being able to save design changes?
Most of us who help here don't use macros so you might have to copy, zip and post your db here - especially since I tried saving a macro for this event and the property sheet shows [embedded macro]. However, it doesn't actually run, which is odd. Then again, I've never used the Dirty event on a control, just forms.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.