Comment 5 for bug 131556

On my system, it takes anywhere from 1 to 10 seconds for the panel tooltips to go away. This means that the Desktop can be blocked for 10 seconds.

I just checked with the tooltips from within Firefox (e.g. back icon), and they disappear immediately.

Note that I have switched off Desktop Effects, since with Effects enabled the time for tooltips to disappear would be even longer.