Lost my root access in the 2.1 rom

[freddroidhead]

I had trouble over using the wifi tether thing in the 2.1 nexus rom so I uninstalled it because it was messing with the camera on the phone. I also uninstalled the superuser whitelist app that came with it and that took away my superuser root access. I still have the ninja icon in my apps though. How do I get root access back? I know the adb thing. Can someone help with that? Thank you.