Subreport shows data in 1st instance then never again

[smilee8]

I have a main report grouped by doctor. There's a doctor header, detail and doctor footer. I have a subreport in the doctor header which works fine, showing relevant data for each doctor in the main report, but then I also have a subreport in the doctor footer which is giving me problems. This has all worked in this same scenario before but I have updated the whole report and now I'm having a problem.

The subreport in the doctor footer is appropriately blank for the first doctor, lists the correct data for the second doctor, and then is blank for all remaining doctors some of which have data that should show.

What are some possible causes of this? I have looked over this and tweeked things many times with no luck.

[June7]

No ideas for cause. If you want to provide db for analysis, follow instructions at bottom of my post.