Joe Harry wrote:The demo seems to work, but why not on my machine? I use firefox 4.0. Has it got anything to do with the other jQuery functions that I have in my page?
Try your local copy without the extra stuff (like your UI .tabs() function) and see what happens.
Use a tool like Firebug to inspect the elements after jQuery UI has gotten hold of everything and see if the markup was changed in a way that would cause the selector to stop working.