Nesting DIVs and background image

Hello there,

Got a website, basically, I have a div called mainHolder. This holds two columns: LeftColumn and RightColumn. I want one big background image to be visible behind the left and right columns. I have set the background image to be back_bg.jpg and left the two columns to have background:none;

Why is the background image of back_bg.jpg not showing through the column divs. I have even tried making a transparent gif and it didn’t work! ARRrrgh, its driving me up the wall!

Any help would be much appreciated, ta much

Stefan

Code below:

#mainHolder{
background:url(…/images/back_bg.jpg) repeat;
width:868px;
margin:0;
padding:0;
}
#leftcolumn{
background:none;
margin:0;
float:left;
padding:170px 102px 30px 50px;
width:682px;
voice-family:""}"";
voice-family:inherit;
width:530px;
}
#rightcolumn{
background:none;
margin:0;
float:right;
width:186px;
}