In html there are two ways to define what the size of the font will be. You can go with one of the browser’s defaults (e.g., “font size = 3”) or you can define what point size the font will be (this is more common with style sheets).
If a website uses a browser default for the font size, the user can then select View / Font Size to make the font display larger or smaller. (At least, it can on a PC — I’m now on a mac and it’s not exactly the same, so I’m going from memory.) This menu gives options like “smaller,” “medium,” and “larger” rather than point sizes. So, if I have poor eyesight and need to see a larger font, I can use this menu to make the font display at a larger size.
When a website uses a fixed font size (for example, the html or style sheet defines that the font will be 10pt), this parameter overrides IE’s view menu. So, no matter what I change the font size to in my view menu, the font on the screen will stay at 10pt. Your site seems to be set up this way.
Hope that helps clarify the issue…
ps If you want an example, go to my website at http://home.earthlink.net/~fov/main.html
Play around with font size in the View menu of your browser. You’ll see that all the text — even the smaller caption about my dear departed hamster — changes relatively when you change the font size in the view menu. Now try doing the same thing on this site… nothing happens.