I think that I have gotten this to work a little better by adjusting some values in this style in your menu_ie.css:
ul#cssmw li span a {
Update the width to be 80px like this:
width: 80px;
I also commented out the padding and height like this:
/*padding: 10px 15px 6px 15px;*/
/*height: 20px;*/
When I did this it seemed to get it all onto a single line, but the level 2 menus were still not appearing. I think you will need to do some more adjusting of the css in order to get the submenus to appear the same. You may want to try adding in a z-index to the level 1 items to see if you can get them to show. Let us know if you have any further troubles with this.