This is not possible with vanilla Seagate Info - if a report is scheduled to run it will always product output - if there are no results then the resulting report will be blank.
What you could do is write a pre-requisite program that runs the query and returns a result code > 0 if COUNT(*) > 0, and 0 if COUNT(*) = 0. You could then set a dependancy schedule on the report so that it only runs if the pre-req job returns a result code of > 0.
Just a thought...
Cheers, Alan Eldridge
Melbourne, Australia