Subreports In Crystal report Showing Blank Page

I am working on crystal reports.I have a Main report and Have merged Many subreports in it.
Now the problem is after every subreport I am getting a blank page.Not getting the Reason .
why this could happen ?
anyone have idea.
My Crystal report contains 1 page header and then 6 to 7 details section containing subreports
and finally the page I missing anything that is causing issue?
please reply if anyone have solution.