Mupad Error: cannot create output file [vcam::new]

The command, and it's result:

plot( x, x=0..5, OutputFile="C:/test2000.jpg" )
Error: cannot create output file [vcam::new]

I have administrator privileges on the system, and it's not "cannot launch mupad process" as here http://www.mathworks.com/matlabcentral/answers/11309-error-cannot-launch-mupad-process-vcam-new-on-mupad-in-matlab.

Why is this happening?

[Billy]

It works if I _don't_ specify a file extension (ie no .jpg), but then the output is a .xvc file, which I cannot open in any other program.