I've got what seemed a fairly simple problem -- replace a table with divs, because I couldn't get the table cells to expand and shrink across browsers the way I wanted. (Worked in Chrome & Firefox, bombed in IE.) So I went to divs with absolute positioning -- worked a charm. Here's what the css looked like on my mockup html page:

       #LeftCol
        {
            padding-top: 10px;
            width: 15%;
        }
        #MidCol
        {
            top:10px;
            padding-left: 20%;
            position: absolute;
            width: 40%;
        }
        #RightCol
        {
            top:10px;
            padding-left: 65%;
            position: absolute;
            width: 35%;
        }
        #StoverBlock
        {
            padding-left: 25%;
            position: absolute;
            top: 720px;
            width: 70%;
        }
... renders beautifully in an empty HTML page. Chrome, Firefox, IE, no problems.

You know where this is going. I paste the same code within DNN's HTML module ... still looks great inside the FSCK preview. Then I save, or preview, and blammo. Text all over the place, doesn't seem to be aware of the existence of the containing HTML module.

Been at this about 5 hours at this point with no luck. Any suggestions would be deeply appreciated. 

Thanks -- the following actually worked OK:

#LeftCol
        {
            float: left;
            top: 10px;
            width: 25%;
        }
        #MidCol
        {
            top: 10px;
            float: left;
            width: 40%;
        }
        #RightCol
        {
            top: 10px;
            float: right;
            width: 35%;
        }
        #StoverBox
        {
            padding-left: 30%;
            float: none;
            width: 60%;
        }