Problems With Linked Tables In A Subform

Hi all,

I am experiencing difficulties with a subform in a database I am designing for a dance group.

First, a little background about the database. There are 2 main parts:
a) a library of CD information and dance information as well as which dances can be done to which songs
b) a tool to plan monthly dance events

Now for my problem:
I have a main form that's built on the PlanProgram table (see attached relationship diagram) and then a subform that runs from the PlanProgramDetail table. Everything works OK up to that point. However, when I go into the subform's record source and add the table Lessons - this is where it "breaks". What happens is when I go back out to the main form and go to enter data in the subform the child field does not behave normally. It doesn't automatically enter the main form's recno_plnprgm number into the subform's field of the same name. Prior to adding the table called Lessons to the subform it did automatically insert the recno_plnprgm number from the main form to the subform.

The reason I want to add Lessons to the subform is so I can update that table's information as well.

Any "fix-it" ideas would be greatly appreciated.

Thanks, Heather