I'm building a skin as follows:

Html:
<div id="wrapper">
        <div id="header"></div>
        <div id="menuPane">[MENU]</div>
        <div id="ContentPane" runat="server"></div>
        <div id="RightPane" runat="server"></div>
        <div id="clear"></div>
        <div id="footer">[USER] [LOGIN]</div>
</div>

CSS:
* {
    padding: 0;
    margin: 0;
}
#wrapper{
    width: 700px;
    min-height: 100%;
    margin: 0 auto;
}
#header{
    width: 100%;
    height: 120px;
    background-image: url('images/headerbg.png');
    background-color: #333333;
}
#menuPane{
    width: 100%;
    height: 40px;
}
#ContentPane{
    width: 350px;
    min-height: 500px;
    float: left;
}
#RightPane{
    width: 350px;
    min-height: 500px;
    float: left;
}
#clear{
    clear: both;
}
#footer{
    height: 120px;
    background-color: #333333;
}



I want the contentPane and rightPane to be side by side, which is exactly what happened when I wrote and checked the html. But when I installed it as a skin on my dnn site, the contentPane and rightPane where vertically aligned. They also collapse heightwise (doesn't the skin installation process read min-height?).

How come they change?

Great! Thanks.

Another question. I'm kind of new to dnn skinning.. If I want to apply changes to the css, isn't it enough to modify the file on the server and then parse the skin in dnn?

How do you mean? The inital naming of the file or a renaming of the file after installation?