A CSS issue

Check your html first. You've got quite a few unclosed tags and typos.

View the source code in Firefox and look for anything in red.

validate your CSS here
http://jigsaw.w3.org/css-validator/#validate-by-input

Validate your HTML here:
http://validator.w3.org/#validate_by_input

just paste them in and you will be told about any errors.

Good Luck

in addition to everything that has been said already:
- get the firefox-plugins "firebug" and "web-developers toolbar". they
are very helpful for creating and validating html- and css-code
- for internet-explorer to show your css properly try to use padding
and margin as little as possible (google for "IE margin padding" and
you will find a lot of people with problems). there are many ways to
get this to work, but no generic solution. personallly i use
transparent borders instead of padding/margin, when i encounter such a
problem.

Excellent, thanks for all the help guys.

MaD wrote:

personallly i use
transparent borders instead of padding/margin, when i encounter such a
problem.

That's an excellent piece of advice, and it is what I also use, but it
doesn't work all the time if there is a special background. Another
problem are floating elements, try switching them from left to right and
switch the order they appear in the html, sometimes it will avoid IE
adding a double margin.

Box models

here's a handy IE toolbar

http://www.alistapart.com/articles/progressiveenhancementwithcss/

Thanks again to everyone for the top notch replies.