We have had so many problems with the FP shared borders that we just do not use them, EVER. These are the shared borders that are turned on from the menu: FORMAT | Shared Borders.
We have found that when you use them on a simple web site with just a few pages they will work correctly however once you start to add more content or get into any type of scripting they can really be problematic.
We strongly suggest you avoid using these and just create each element on your pages from the start using "include" commands instead.
For example: Create a page as a footer. Call it footer.htm. GO to menu: INSERT | Web Component | Included content (on left) | Page (on right) | Finish. Now browse to the page footer.htm. Hit OK. You will see it has appeared on your page.
You will need to have this on the bottom of every page but you will avoid the long process of removing all those nasty shared borders at a later date.
HINT: If you now, right click on the included footer; you can copy and paste it on the bottom of your other pages without having to do the full menu thing over and over again.