The downloadable Version of jquery.ui under http://code.google.com/p/jqueryjs/downloads/detail?name=jquery.ui-1.0.zip contains a Bug that prevents at least IE7 from working correct.

In ui.slider.js on Line 31

change: function(e, ui) { cur[0].value = ui.value; cur[0].setAttribute("value", ui.value); },

The last comma "," raises an error in IE7 (Firefox 2 works though). The Demo-Versions doesn't conatin this bug.