if the writers of FileMaker are listening, It's 2015. A LOT of workstations have multiple displays.
Actually, they probably aren't here in the "self help" section of the forum. If you want to suggest improvements for future versions where they will be seen by those that decide what features to include in future versions, try here: http://www.filemaker.com/company/contact/feature_request.html
As to the multiple monitors and such, been using 13.5 in windows 7 on two large monitors connected to my lap top all day. Right now, I'm just using the display that comes with it and when I open 13.5, I don't see this issue. but you system configuration and OS are not identical either...