When the report writer tries to print any band, it looks at the defined height to see if there's enough room to print it. If the detail band is near the bottom of the page, and you've defined it as 5" tall, the report thinks it doesn't have enough room to print. It doesn't bother to evaluate the context of all the fields to see what is ACTUALLY going to print.
For memo fields, just define the object as one line tall on the report, and mark it stretch with overflow. Define the height of the detail band as only 1 line tall. That should take care of any problems.
You mentioned that reports aren't your expertise. I'd like to suggest that you read my book, The Visual FoxPro Report Writer: Pushing it to the Limit and Beyond. It's available from Henzentwerke Publishing (
www.hentzenwerke.com). It goes through all the basics of how to use the VFP Report Writer.