Bootcamp/Terrain Stuttering/Lag Issue - Any Ideas?

Has anyone else noticed behavior like the embedded video:

Hardware specs for the computer running the Bootcamp demo:
Processor: Inter(R) Core(TM)2 Quad CPU 6600 @2.40GHz 2.40GHz
Memory (RAM): 4.00 GB
Windows Vista
3D Card: NVIDIA GeForce GTX 460

So this computer can run Crysis, but seems to be choking on the Bootcamp demo.

I've noticed that the problem is most noticeable when zooming in/out. It even happens with trees and vegetation turned off. The effect does lessen if the "pixel error" on the terrain is increased.

This leads me to believe something is wrong when the terrain is re-building its geometry.

Things I have tried:
- Updating the video card drivers
- Uninstalling and re-installing web player (you can see it is the beta 3.4 player in that video)

Any ideas? Or has anyone seen this themselves?