In the new "Calm" skin, when I switch to mini mode, the window shrinks to the size of the mini mode, but it doesn't load its bitmap; you only see the bottom left-hand corner of the main window. The buttons of the mini mode "pop up" as you move your cursor over where they should be.
This happens most of the time. Sometimes when it doesn't work, I got it to work by dragging a panel out before activating mini mode. If you can't reproduce it, I could upload a picture of it. Maybe it's a problem with all the blank space the author left in the mini-mode bitmap (so the mini-mode would appear in the bottom left corner instead of the top right as it normally does).