Oh dear.

I've never seen anything like that before. Where does everything go? It seems to happen only in FF too. IE and Opera are fine.
You have some validation errors.
http://www.htmlhelp.com/cgi-bin/validate.c...s&input=yesMost are because you declare that you use XHTML, but you don't. Change to a HTML doctype and those errors will go away.
The othere errors are of this type.
CODE
Line 120, character 23:
<h2><a name="1" id="1"></a>Low Tech - High Effect</h2>
^Error: value of attribute id must start with a letter, not 1
"ID and NAME tokens must begin with a letter ([A-Z a-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods ("."). "
http://www.w3.org/TR/html401/types.html#h-6.2This is a longshot, very long, but start with correcting those name and id values. As said, I've never seen something like this, but I have seen "numbered" anchors make other odd stuff happen.