You do not need to link the cave view object to the main viewpoint, it is automatically handled for you. So you can remove the following 2 lines of code:
Code:
link = viz.link(view,viz.MainView)
link.setDstFlag(viz.LINK_POS_RAW)
When you specify both position and orientation for the cave tracker, that sets the cave in stereo mode which means it will only display correctly when stereo is enabled.
Does the frustum look skewed when you view the screen from the point of view of the tracker? The whole point of vizcave is that it skews the frustum so that everything appears physically correct from the point of view of the 3d tracker.