Gene,
This is usually related to a problem with one of the contained controls not being able to bind to it's data source. Since you saved the form as a class you basically hosed the DataEnvironment the form had. You'll have to get the formset DE setup to what the form is expecting.
>In the formset's INIT, I call the following code:
>
>THISFORMSET.ADDOBJECT('frm_beg','frm_beg')
>
>and recieve the following error:
>"Error instantiating the object."