Actions to reproduce: Open two windows. Have the first window enter TabCandy mode. Drag a tab from the second window into the first. Expected Behavior: Tab is added to TabCandy UI of first window. Actual Behavior: Tab fills frame on top of TabCandy, leaving tabs, menus, and other UI elements unreachable.
Seems to be fixed now
Mass moving all Tab Candy bugs from Mozilla Labs to Firefox::Tab Candy. Filter the bugmail spam with "tabcandymassmove".