If you fire up the FRC cRIO Imaging Tool again it should be able to find the cRIO and tell you what it's IP address is currently set to. The reason you can reimage the cRIO with a mixed up IP address is that the Imaging Tool
will look for the cRIO at several common potential addresses and display the IP address at the top if it locates the cRIO.
You don't have to reimage the cRIO with the tool, just start it up to see where the cRIO is.
The pinger utility rogeringalsbe refered to is posted in the whitepaper section at:
http://www.chiefdelphi.com/media/papers/2177
If you're still having trouble by this weekend is there any chance you can get to the workshop at Poly Tech in Brooklyn on Saturday with your system? We can work on it there.