So it sounds like your sub report is still running and what you are seeing on the blank page is the main report GF3 with a subreport with some secitons suppressed but not the entire report. Correct?
As Sastry indicates you can set the property of the sub report by
right click on the sub report
select format sub report
select Sub report tab
mark the 'suppress blank subreport' as true
also in the main report you can use the section expert to mark that GF section to 'suppress blank section'