I remade the website for my work located at http://www.midatlantictechnologies.com. It looks fine in IE but when I try opening it up in Mozilla or Firefox it shifts some. Any ideas?
Mozilla and/or Firefox are proper, standards-compliant browsers, so they highlight the problems with your code. Internet Explorer is more forgiving of problems, so it is not a good idea to design with it.
You have a very simple design, so I recommend rebuilding the site without frames, using plain old HTML and a little bit of CSS. You will find it faster, easier to work with, and more compatible with the different varieties of browser.
Some hints and tips on Web development are in my site: