ie6 Sliding Doors problem rollover

I have an <a> tag which uses the css sliding doors technique to show the rollover state

a.task_link {
width:220px;
height:241px;
float:left;
position:relative;
margi开发者_Go百科n-right:20px;
display:block;
text-decoration:none;



}


a#task  {
    background:url(/images/task.jpg) no-repeat;

    }

a#_task:hover {
    background: url(/images/task.jpg) -220px 0px no-repeat;

    }

The problem is with ie6 I get a flashing/blinking of the background image, any solution to this?

Thanks,

J.

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Add position:relative or zoom:1 or overflow:hidden or something that will trigger layout without breaking usability.