I've never really used it so I'm just tossing out ideas. FP is old at this point so I'm not sure how many here would be familiar with it. FP is now called Web Expression and is in it's 4th edition as well. No, I don't use WE either.
To clarify that, it's not like FP was renamed to WE. FP was tossed out, and MS came out with WE - a totally different product.
Regarding the original question, I wouldn't be surprised if the FP page viewer was having trouble parsing some new code on the page that came out in the 21st century.