[AccessD] Access 2003 issue

I have an app that is Access 2000 MDB and it runs fine under both A2000 and A2002, in A2000 format. 

Today I loaded it to run under Access 2003 and there is a problem.  It appears that the syntax 'Me.Requery' does not work.  The Me.Requery is in the After_Update event of a combo that serves to filter the records appearing on the continuous form.  The form's RecordSource is a query with the combo boxes referenced like this:
 
Field:IIF(IsNull(Forms!etc!cboFilter),True,underlyingField=Forms!etc!cboFilter) 
Criteria:True 

I can't see anything in KB.  Because the combo is on a subform of a form that's part of a Tab control, I'm going to mess around with the way the combo is declared in the Query, but this is shootin' in the dark stuff. 
  
BTW, I tried converting the app to Access 2003 format, but nothing changed, the problem still exists.
 
Any ideas?  TIA 


Stephen Bond 
Otatara, South Island, New Zealand