[vonofterdingen]

Are you familiar with the config.ini file? If so, check to see if the initial lines look like this, except that the first two lines should show you screen resolution. In particular, check your FullScreen and EnableResize values:

[window]
width=1600
height=1200
ColourBits=32
DepthBits=24
StencilBits=8
ChangeScreenRes=1
FullScreen=1
DrawIfNotFocused=0
EnableResize=0
EnableClose=1
SaveAspect=1
Use3Renders=0