Vertical Cascade Menu Options

[Al Jones]

I've wanted to replace the letter menu (left hand side) that I have in my web site for quite a while. I went looking for a decent accordion style menu and found this one that looked like it would be fairly easy to implement and do what I wanted.
Changed things around a bit so that the menu, by itself, looks like this.
Okay, so far so good. Until I try to drop it into my existing web pages where it does some really odd stuff.
I've looked for conflicts in the CSS - but not being good at it, I found none. Can any of you gurus offer some pointers for me.
Note: the web pages are put together from php includes, there's actually very little code per page, everything is drawn in from includes that work in the "original" version and don't in the "trial" version.
//al