loss of focus problem

I'm developing a Delphi 2.0 application.  On one form I'm noticing a
focus problem.  Here's basically what happens:

I click on a button to bring up the dialog (modal, although nonmodal
doesn't seem to affect it).  The dialog appears and focus is on a button
as designed.

I switch to some other application (wordpad, etc) and switch back.

Upon return, no component has focus.  I've hit tab about 50 times
thinking maybe focus was just on something else, but this had no effect.

Other similar forms in the application do not experience this problem,
but I can't discern what the difference is that causes this problem.
Anybody have any ideas or suggestions?

Thanks in advance,
Jeff Bennett