I have a problem with the size of the main MultiAVCHD window.
My screen resolution is set to 1366*768, but the bottom part of the program window is not visible (its under the tray, even if the upper border of the program window is on the top of the screen). When i hit the maximize button, the program window maximizes itself and covers the whole screen, but the bottom part is still invisible (stays under the system tray.)

I can't change it... ANd there is nothing important in the lower part of the GUI so you should have no problems.

I had the same problem which I fixed simply by press & hold the control button and then resize the window by pressing the minus( - ) button...