A problem arises with allowing a sub-summary part(s) to ‘allow part to break across page boundaries’. If this option is turned on, the contents of the part will show in the parts above it (body, header, etc). This is true whether printing or viewing it in Preview mode. If the option is turned off, then it displays as expected.
This is apparently a problem with FM11 specifically. I tested and confirmed that this problem didn't exist with FM10.
This is on widows OS clients. I can't confirm if this problem is on Macs or not.