The quotes make things with spaces work. @MsgFrom wouldn't need quotes because names don't have spaces. @MsgData needs quotes to relay something with more than one word in it.

Using a vanilla build from the April 3 17:29:18 zip with default plugins. To reproduce: Alt-left click on a bunch of different items - this makes them stay up after the mouse is released. After 3-4 items, the last window to be brought up stays active, changing to whatever item you clicked on. Any it...