Well think about it Car Comp.... why does it do that?
So when a user clicks it... it stays open until you select what you need... that will always be an issue w/ the javascript and the code your using to do the floating navbar. One hint is to add some extra spacing near the bottom of your footer so if there's anything pertinent down there i.e. links it will not cover them and they can scroll a bit more to see everything required. Nice concept I had the same idea many moons ago but due to that error and some member complaints removed

but also remember to add in a close box so they can move it out of the way if they wish and you might have it! Some "members" on some boards do not share the same overall opinions!
S-MAN
Edit: Also, do like I did... offer two versions of the navbar via conditional coding, so everyone and new users see the old navbar BUT guys who read the forums know you have a thread up describing how to join a public usergroup that changes their navbar to a floating one for uber easy navigation

- just a thought and yes it works!