Filter and check box not working when form is put in sub form

Strange problem I have an option group that after the update (3 choices) I set two variables to a date range and then I also include a a value for a field (boolean) as the remaining criteria for the filter

the filter is below and works flawlesly as a form by itself

Me.Filter = " [Projected Start date] Between #" & dtStart & "# And #" & dtEnd & "# AND [TWLA] = -1"
Debug.Print Me.Filter
Me.FilterOn = True


If I remove the "and twla = -1 " and filter just by the date range - I can right click the check box and filter further for -1 0r 0

When I embed the subform I get a double whammy of headache
clicking the option group pops up a parameter value for the filed TWLA - which itdoes not when I use the form as a main form - in addition the check box is blue and does not allow me to filter - it has the exact properties of 3 other check boxes that function fine.

Any ideas why I get this behavior?