I'm just starting with Unity (Mac version). When I first opened it, there was a sample game, AngryBots open. I was able to navigate through the scene by holding right-click and using the WASD keys. After creating a new project to try some tutorials, this no longer works. A and D work for sideways movement, but not W and S for forward and back. However, if I hold W or S down for a few seconds, the near or far clip plane slides through my scene and hides/shows everything from view. I tried creating another new project and still have the same problem. Any ideas? Thanks.