Dear team.
I download today the new release of JQuery-UI 1.8.1 and when change it into ours projects, I detect a problem using Firefox. When I search the problem, I find that the error is that the expressión "+ ++" used 4 times in the jquery-ui.1.8.1.custom.min.js create a problem when ours systems re-minimized the expression directly to "+++".
Now, I fix the problem addind a +(++...) in the minimized js.
Josep.