Cluetip does not open correctly after the second click

I am using the Cluetip plugin in a simple css menu structure. When the first item is selected and the link is selected, the
cluetup window opens as expected. When the secone menu item is selected and THEN I go back to the first item selected, the cluetip window opens full screen instead of in the 450px window as at first. You can see this at my demo site:

http://www.transeeq.com/menutest/menu21.html

When I ran firebug in Firefox it shows $cluetip is undefined after the first click but not sure why or how to fix?
Thanks to all,
kboy