I have a page with Tabs setup and working fine - all content loaded prior to calling tabs(), no ajax loading. Yesterday, I had a requirement to add a new tabs element on one of the existing tab panels which would create nested tabs. Everything worked as far as rendering (in Firefox, OS X, Snow Leopard - my testing environment - didn't test anything else). However, when mousing around, weird things were happening with the "state" of the tabs in both the parent and child tabs. The state would flick to hover and immediately back - even when I was still hovering. Clicking on any tab did not always switch to that tab - sometimes clicking several times was required before it would switch to that tab.
I can post sample code if anyone wants to help debug...
Because the demo used "http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js" (aka the latest version), and it is not compatible with "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.0/jquery-ui.min.js", the page fails.
Try it with a more current UI or an older jQuery (1.8.3)