New Member - Content not pushing bg down

I have content that when it expands downward, it doesn't push the background down. I have tried a Clear:Both in various places including before the end of the content div, to no avail. I did also remove the min-height attribute on the content div.

The problem can be seen here:

batterytex.com/product/detail/LOCK%20NETICS/k380-001/dl-30

Any help on this problem much appreciated!

UPDATE: I have got it working (as far as pushing the bg down) but my right column is now stuck down below (it should be at the top of the page). I tried vertical-align top, changing its width to be really small, but neither worked.

Take a look here if you can help!:

newbattery.geodesicgrafx.com/model/jet-book-386sx

here's the css i have, which i probably should have posted already!



.details-box-main {

padding:5px;

padding-bottom:65px;

width:965px;

margin-left:0px;

margin-right:35px;

background-color:#f1f1f1;

position:relative;

border:solid #0E356C 1px;


}



.details-col-left {

float:left;

position:relative;

overflow:hidden;

}




.details-col-center {

float:left;

position:relative;

overflow:hidden;

width:330px;

padding-left:25px;

margin-bottom:20px;

}





.details-col-right {

position:relative;

overflow:hidden;


}