There was some kind of bug with mouse_force in 6.22 and upgrading to 6.3 made the program go crazy. If you held down the right mouse button to rotate the view and then let up on the button, the view would continue to rotate. I fixed this, although I have no idea why it would do this given the way it was coded:

http://www.geocities.com/hainesrs/isometric.zip - 505KB...includes all code, resources, and demo level