dkret3 theme dropdown menu doesn't work in IE7

Hi I am fairly new to wordpress and wondering if you could help me.

I am using the dkret3 theme and have added several sub-pages to my site, which the theme automatically adds as dropdown items from the main menu. While this works beautifully on Firefox and IE8 and 9, it looks completely distorted in IE6 and 7 and has made the main menu items appear on the left side over the content of the page. While I have pretty much given up with IE6 as it doesn’t support the hover command, I would really like to have the site working in IE7.

My URL is http://www.lizbarron.co.uk/wp if anyone wants to see what I’m talking about. Please forgive the content, it is just filler at the moment until I’ve sorted the layout!

Thanks for your help!