Hi, first of all, great work!. Unlucky me, I have an issue here. First, I have a MainWindow with a main tab. Then, this main window has a floating item list, which at certain point I add a tab to it. Up to this point it works perfect. When I expand the floating item, and a window is created, whenever I try to dock it to main window, it shows an empty tab, and my tab (without header). I'm using MVVM pattern with MVVMLight toolkit. Any suggestions?