[BNM] WordPress javascript problem with firefox

[Mike Halsey]

Hi all,

I've just switched my wordpress blog www.thelongclimb.com over to the Gotham Nights theme from www.evaneckard.com 

It's really nice but I've had to work out some stuff in the code.  One things is eluding me though.  In the right hand pane is a cool javascript menuing system with three tabs, tabs that flatly refuse to work in Firefox.

Does anybody have any clues as to why please?  I'm stumped.  

Thanks,

Mike