Tracy:

I know that you are a very experience VFP. I assumming you are using VFP 8.0, the rules of modal and modaless changed and also they added another property read(2) see this extracted from the help

"
Specifies the parameters passed to the form or form set.
If a form set is run, the parameters are passed to the form set's Init method if the form set's WindowType property is set to ModeLess (0) or Modal (1). The parameters are passed to the Load method if the form set's WindowType property is set to Read (2) or ReadModal (3).

"

I know from the pass that this modal and no modal situation cause us a lot of trouble and that new property readmodal can be the clue.

I read your code and did not see anything wrong, but commenting the section of code previous to call the form to see if the problem continue.

Again, I am clueless like you. I will keep the eyes in this post.