Just had a recurrance of this today on the latest updates. I do not seems to be able to reproduce this with debugging enabled. As per your comment re-raising priority as it is still occuring with the latest code.
My feeling is that the bug occurs when there are near simultaneous notifications from 2-3 applications. I just triggered it when hitting play and then hitting down-volume a numbers of times (music was loud) and an xchat notification attempted to appear. Immediatly I could no longer adjust my sound volume and both rhythmbox and xchat greyed out under compiz ... wait about 40s and then the volume OSD appeared and zoomed down to the bottom and my applications returned from limbo.
Just had a recurrance of this today on the latest updates. I do not seems to be able to reproduce this with debugging enabled. As per your comment re-raising priority as it is still occuring with the latest code.
My feeling is that the bug occurs when there are near simultaneous notifications from 2-3 applications. I just triggered it when hitting play and then hitting down-volume a numbers of times (music was loud) and an xchat notification attempted to appear. Immediatly I could no longer adjust my sound volume and both rhythmbox and xchat greyed out under compiz ... wait about 40s and then the volume OSD appeared and zoomed down to the bottom and my applications returned from limbo.