Foxpro Advisor published an article in October 98 by Christof Lange called "Getting the Most from the Report Designer". A section of this article was about "Getting Rid of VFP's Printing Window". If you don't have access to that, basically just create a UDF that will do the following:

if wexist("Printing...")
move window "Printing..." to -1000, -1000
endif wexist("Printing...")

Then in the OnEntry expression of the Detail Band - make a call to this UDF.

Hope this helps.
Yuanitta