its not your FF, it does it for me too. I wil be interested to hear the answer

I'm not sure this will work but try the following:

In your _main.php file in the /custom directory change the following line near the top (linking to your style sheet):

<link rel="stylesheet" href="custom.css" type="text/css" />

To this:

<link rel="stylesheet" href="http://www.ironwillradio.com/IchKampfe/EvoBlog/blogs/skins/custom/custom.css" type="text/css" />

Basically we're getting rid of the relative link and replacing it with a direct link. I got a similar problem to this after I installed the latest xmlrpc patch (or whatever those letters are). I'm not sure this will help, but it seems something is preventing or misleading Firefox from using the correct style sheet.

Let me know if it works because the back office of one of my blogs lost its skin after I installed the patch and I haven't tried to fix it yet.

I'm no expert, but here's what I found:

When I put in a background image in the "body" section of the CSS file, it overwrote the background for the main post area and sidebar in Firefox but not in IE. To force the background in Firefox to be what I wanted it to be, I added background parameters for the Sidebar and Posts (.bSideBar and .bPosts sections in the CSS file), and that forced a background color in both IE and Firefox.

Hope that helps.

Your css is being ignored by FF, it can be pulled up manually if you have the Edit Css plugin.

I've seen (and cured) this before, unfortunately I'm blonde and have a naff memory, so don't quote me on this :-

IF I remember rightly, it was to do with the way the file was transfered to my server (it was transferred as binary and should have been ascii or vice versa). I think I cured it by opening the file on my server and saving it again as plain text.

¥

Error: The stylesheet http://www.ironwillradio.com/IchKampfe/EvoBlog/blogs/skins/custom/custom.css was not loaded because its MIME type, "text/plain", is not "text/css".
Source File: http://www.ironwillradio.com/IchKampfe/EvoBlog/blogs/index.php?blog=2
Line: 0

In FF go "Tools->Javascript Console"

Yer i have no idea what this error means, just google it.
And im amazed that CSS can change your layout that much!
I just use CSS for common properties, not my whole page design, so good work there!

Btw your skin strikes an odd resemblance to http://demo.b2evolution.net/HEAD/blogs/index.php?blog=2

Thanks for all the suggestions - I've been trying them all. And the answer is...

I created an .htaccess file with this:

AddType text/css .css

and put it my custom folder.

I found the solution in a few spots on the web.

I guess the issue has more to do with my particular Apache server but I've never had any other trouble with css before.

Anyway, that's what worked for me. Thanks again for all the suggestions.