Multiple Window/Canvas crash

SuperStrict
Framework MaxGUI.Drivers
Global BMaxWindow1:TGAdget
Global BMaxCanvas1:TGadget
Global BMaxWindow2:TGadget
Global BMaxCanvas2:TGadget
BMaxWindow1:TGadget = CreateWindow( "Window1", 120, 120, 640, 480, Null,WINDOW_TITLEBAR|WINDOW_CLIENTCOORDS )
BMaxWindow2:TGadget = CreateWindow( "Window2", 240, 240, 640, 480, Null,WINDOW_TITLEBAR|WINDOW_CLIENTCOORDS )
BMaxCanvas1 = CreateCanvas (20,20,320,240,BMaxWindow1)
BMaxCanvas2 = CreateCanvas (20,20,320,240,BMaxWindow2)
End

This crashes in release mode but not in debug. What am I doing wrong? I only want 2 windows, each with their own canvas.

Does importing...

Import BRL.GLMax2D

...help at all?

Thanks heaps, that works fine. I don't understand why though? I can get one window and canvas without the extra import. Why do 2 canvases (canvii?) require that import?