I have a skin that has a div within a div and they both have backgrounds. Since DNN puts everything in a table, firefox is putting extra space at the top of one of my rows. You can see it here sentinelhealthcare.org. It is only in FF not even chrome or safari. Does anyone know why? I have been working on this for days now. I have attached my ascx and css

You should make sure that your skin is set to run in XHTML compliance mode.  That will minimize the cross-browser differences.

You might find this tutorial helpful in tracking down problems:  Troubleshooting DotNetNuke Skins

While those are good videos, unfortunately, I use those tools and already knew about those tips and tricks. I can give you a little more information. I have pinpointed this down to a table row being taller than it should be. In my skin I have a div with a background image, and then another div centered inside of that with a background image. Both of these divs are the same height. When DNN creates the page it puts those divs in a table. However that table row is 10px higher than the divs. Somewhere I am getting the extra space and I don't know where. I don't know how to specifically set the height of that table row because DNN creates the table, it is not in my skin. Any other ideas?

Are you referring to what I see as a light blue line 11 pixels high just above the About Us section?

Exactly

If you look at the page source of your home page, you will see that there are two body tags. I don't know why that's happening. It's not in the skin file that you posted. Is that the skin that you are using?

Are you sure you got the right file? It was in the ascx file. I just downloaded it again to double check. I removed the body tag, but that didn't fix it. Any other ideas? I appreciate the help.

Look through your module contents.  Look for p tags surrounding a   and outside of the table structure.  It look to me as if you have some tables in some of your HTML modules.

The problem was an "empty" Text/HTML module that wasn't quite empty. It had a blank surrounded by p tags -- a result of FCK Editor putting "something" in empty space. The result was that the content in the pane was taller than the pane.

Removing the extra blank fixed the problem.