Nature of the beast, a subreport is a seperate object.
Try passing values using shared variables from the main report to the subreport and using the subreport to display/export everything if that's an option. Works here using CR XI.
The best bet would be to eliminate the subreport, but of course this is dependent upon many factors and one line posts get little action here because we have nothing technical to on.
Please at least post your software version.
-k