PDF generation not respecting right margin

Hello FM community,

I'm relatively new to FrameMaker and I'm hoping you might be able to help me out with an margin issue I've been experiencing lately, probably the last two weeks or so.

I have the TCS 3.5 which includes Frame 10 and Acrobat X Pro.

I use FM to produce my company's user manual.  I use a couple of master pages for different types of pages, like section pages and title pages, but the majority of my manual  uses the same master page which is just a simple header, footer, and giant text frame in the middle.

Up until recently (about 2 weeks), everything generated fine when I went to save as PDF. 

Recently, however, whenever I save as PDF, Acrobat distiller and/or FrameMaker is not respecting my right margins and will generate OFF the page.  The text displays perfectly in FM, but when I generate as PDF, random pages print outside of the right margin.

Has anybody experienced this before?  Forgive me if this has come up many times, but it is new to me, and I would appreciate any newbie tips on how to troubleshoot this issue.

This is how it looks in FrameMaker:

This is how it generates as PDF:

Thanks so much!