Set a variable in a formula prior to running the subreport in whatever section is appropriate (you can right click any section and select insert section below, move the subreport in there, and then place this formula in the section the subreport was in), such as:
whileprintingrecords;
numbervar SuppressPageHeader:= 1;
Now reference the vairable in the suppression for the page header, as in:
whileprintingrecords;
numbervar SuppressPageHeader;
SuppressPageHeader = 1
Select New Page Before in the subreport section formatting, and you should be good to go.
If you want the page header to continue after the subreport finishes, reset tha variable to 0 after the subreport runs:
whileprintingrecords;
numbervar SuppressPageHeader;
SuppressPageHeader = 0;
-k