IE/FFox text display differences?

I have a page loaded on my site, and the text displays different in IE7 than it does in FireFox and Chrome.

The page is:
http://www.familyfunmagic.com/Welcome.htm

I have screen shoots of the differences here:
http://www.familyfunmagic.com/Screenshot_IE.jpg
http://www.familyfunmagic.com/Screenshot_FF.jpg

How can I change the source to get this to display consistently?
Ed

Validate for your lists of HTML and CSS errors. You are also using proprietary markup that only works in IE and not modern browsers like Firefox.

Finally!! I have gotten enough time to work through my "ToDo" and "HoneyDew" lists to validate and correct the page in question. The w3c validator likes it.

http://www.familyfunmagic.com/Welcome.htm

Unfortunately, FireFox _still_ doesn't like it! The first box goes whacko with font size, and the plain text in the third and following boxes looks anemic, like a bad typewriter ribbon font.

Is there any hope for this page?
Ed

I'm gonna move this over to the CSS forum.
Looks like it belongs there better.
Ed