As we rushed to get Quiet compatible with Lion before the official release, a new bug sneaked in that only affects Snow Leopard. The bug is causes the Dock to be hidden even after the user exits isolation mode. If this happens, please quit Quiet, and your Dock should re-appear.  The temporary work-around for this issue is to deselect "Hide Dock," and you should be able to use Quiet as normal. 

Please note that this but only affects Quiet 1.2 on Snow Leopard. 

Quiet 1.3 is available today, which addresses this issue.