We have a real puzzle on our hand!
Best way to describe it is via the reference pages.
That is if you look at this page for example:
the font type on the Navigational bar on the right is correct.
However, when one clicks on certain buttons on that on that Navigational bar on the right,
then the font type of the Navigational bar on the right is messed up, such as:
I have checked and double checked it, and see no difference in the CSS code of the 2 pages.
So what is causing the font-type to be messed up in some of the pages!!!