This is the structure of your Main report.



RH [Set to show the Header & Footer]
PHa [Show/Hide Header]
PHb
GHA
GHB
DetailsA
DetailsB
DetailsC
GFA [Set Don't Show Header/Footer][Show Next Section on new Page]
GFB (Contains SubReport) [SubReport Shown with out Header & Footer][In Subreports Footer set the Sub Report has been completed and reset the Header Variable to show the header and footer][Also if the footer is not properly shown then you have to reset it in the footer after hiding/showing the footer]
PFA
PFB [Show/Hide Footer]
PFC

In this report you have to play with the time and records. First you have to dive in the report and think when to show and hide then accordingly adjust the variables to behave the report accordingly.

If you are unable to do then please attach the report with saved data.