Hmm maybe I'll have to put in a config option for not using the hertz parameter. I think the above will work for you though.
you can also try
but that causes an uncontrolled frame rate so scrolling the map will be way too fast.
you can also try
screen mode:800 x 600 x 32 @ -1
but that causes an uncontrolled frame rate so scrolling the map will be way too fast.