Is this a DYMO label, and on a Mac? If so, change printout orientation.
In FileMaker 11 they had things aligned by pixels, but in FileMaker 12 they have things aligned by points.
So although they tried to make things align and the same size as 11, things will be off just a little.
There was a bunch of company files that we had to update, and that kind of problems along with other layout things were a little off.
So had tomanually go through all the layouts in each file to check. What we had to do to fix it was change the font to something like Bold or a different font, save the layout, and then change it back and save it again.
It was a bit of a pain.