I'm not sure what you mean by this:
"and I centered the text I pasted into it. It defaulted to Right Justify. Looks good."
Did you select center or right justification for your field when you say it "looks good"?
Sorry about not being as clear as I could have.
In FileMaker I selected the text in the footer and I "Aligned Text to Center". It aligned it properly in FileMaker.
I then went to a web browser on another machine and pulled up the site , selected the shared database, and when I looked at the footer the text was right aligned.