Pardon me, but it doesn't work for me. ;x It could be because I'm using IE; and it might work for me at school, but I'll just tell you what happens for me? =]
a) The DIVs get cut off. I'd suggest expanding them a good 100px or maybe even 50px.
b) I don't see a graphical switch between icons, if this was your intent? Instead, It just links me. You could probably do what Vanya did, and link the third icon, though? :)