I have dual monitors setup as Dualview. Using VLC 0.98.a
When I double click the window to go to fullscreen, it is sent to the secondary display. This occurs regardless of whether the window was on the primary or secondary display when I double clicked it to go fullscreen.
I was able to work around this and get proper fullscreen on the primary display by enabling "Enable fullscreen interface" and then "Minimal View."
But going only to the secondary display is not polite behavior.