I have found the exact same bug.
When the container of the accordion is set to display:none when creating the accordion, the accordion does not display properly, and throws scripting errors in IE (but not in FF).
However, if you use visibility:hidden, when you change the visibility back, the accordion renders perfectly, no problems, however the jQuery UI.Tabs render incorrectly. What happens with the tabs:
The tabs load and work fine, however the first display tab is the only one to appear ok, but if you select any other tab, the background color for the next tab displays incorrectly (perhaps a class does not get set?), however if you re-select the first tab, and then select the same tab which originally had an issue displaying the first time, it will display correctly the second time. This will occur for each of the tabs (excluding tab index 0).
From further examination, it appeares display:none only breaks the accordion. Unfortunately, I do not have time to investigate the cause/solution for this bug, so any help from the jQuery UI team or fellow contributors would be appreciated.