CSS help?

I recently started using Firefox. Now that I have I can see that the Jewish High Tech Community website that I built doesn’t display properly and doesn’t validate (honestly, I didn’t check this out when it came out fine in IE, mea culpa). I could use some help, if you care to take a look.

Some details:

• If I leave out the doctype declaration, everything looks good in IE; if I include it, strict or transitional, IE displays the same bad stuff as Firefox.
• The CSS validator gives me hassles for the use of a width attribute.

Uggh!