Problems with sf-menu

Hi all,

I am having issues with the sf-menu.

Basically when the drop-down menu drops down it pushes the content under it down.

Also, when the drop-down menu is down there is a empty space between the menubar and the drop-down content.

Any ideas how to get this fixed? I have a feeling it's to do with the css but I don't know what to check or tweak.