When you check the settings in Part Setup for the body, what page break options, if any have you selected?
BTW, This part of the forum is intended for reporting possible software bugs. If you need help using FileMaker, you will get more help, more quickly if you post your question in the FM Pro Forum.
All are set to break the bounderies, I have tried every option... I spoke to FM support, they asked me to get on the forum, as the guy I spoke to had also encountered the same issue !
I believe that the issue is that the field (the description field) cannot be split onto another page, hence, the issue.
I once had a similar issue and somehow it was linked to the lines. In particular, when I removed one of horizontal lines, the problem disappeared. Could you try to copy the layout, remove all the horizontal lines, and see if this helps.
Thanks, for the suggestion - no luck... I have also tried to change the product description field to a merged filed, and still the white gap is there...
This issue has been previously reported for many earlier versions. Seems like FMP 12 also has the issue.
For More Information see: Frustrating subsummary bug
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip