Glad to hear that it works under Vista.
The "waves" are caused by LOD algorithm. In current implementation vertex buffer is updated every time when the camera is rotated. This causes low performance and visible LOD artifacts.
Later I'll add an implemetation of the same algorithm without thee need of updating landscape when the camera rotates. It's less effective in vertices usage, but free of artifacts and much faster when user rotates the camera heavily.
Current implementation is perfect for top-view games, like strategies or fly sims.
The alternative will do well for first-person view.