My apologies that I shot that reply back without looking at your code and assuming your setup. The actual select you should be targeting looks to be #menu-menu. With this at your target your css should be:
#menu-menu {
width:928px;
}
#menu-menu li:last-child {
position:relative;
float:right;
}
Hope that works! Also, you should probably d/l firefox’s firebug. It’s an amazing tool for working on and figuring out items like this.
You need to d/l and install firebug(http://getfirebug.com/).
This is works with firefox to allow you to point to/change css on the fly. Once you find your solution you can go into the code and change what needs to be changed.
The css properties you most likely need to change are line-height and margin.
in your CSS try
#nav li:last-child {
position:relative;
float:right;
}