Nav Drop Down Hover Issue

On the above site, when I hover over an item the drop down appears, but then when I try to roll on to the drop down area it disappears. Now I know it looks like their is a gap between the anchor and the drop down box, but there isn’t - cos I put a background colour on my anchors and it works fine, take away the colour and it stops working.

This is only happening in IE7 and IE8, not even looking at IE6 yet.

Any ideas?

Slight update, I have changed the hover left from auto to 0 and that seems to have fixed it, oh and I added a float:left to the anchor.

Slight flicker, but I can live with that.