I am having problems with a control in one of my subforms.  

In this subform, I've set the value of a combo box to default to the value
of a control on the main form.  

When I view or first click into the new record line in the subform, the
default value appears to be working fine.  However, when I start entering
data in the next control in this new record, the combo box value changes.  It
seems to be defaulting to the name of the form itself.

I do have another form/subform which I set up the same way, and it seems to
be working fine.  The only difference I can think of is that the one which is
working is based on two tables - not a table and a query.  Maybe I have the
relationships set up incorrectly?

Any help would be greatly appreciated!  Thank you!!