I see your problem.
You used display: inline-block; on your li. It's not supported on all the browsers, and not the best way to style elements that are meant to be floated.
There are two ways you can make this work.
1. Put a div around the ul and float to the right. Then float all the li to the right also.
Your tabs will float to the right from the top of the stack. You will need to change the order of your tabs from the html to keep the current order. So your "Home" tab should be the last in your html. (This is the easiest way)
<li style="float:right">Client List</li>
(You're going to use css to declare the styles, this is just and example.)
2. Another way is to put the div around your tabs and float:right;. Then float all the tabs to the left. You don't need to change the order of your tabs using this method, but you will have to play with the width of the div and test it in IE to make sure there is no surprises.
The safest way is the first one.
I hope it helps. Let me know if it works.