Thanks Bronxteck. Actually, your first suggestion contained the solution to the problem. I just didn't initially understand what you were telling me. I found the networking.plist (which was called something else that I don't remember now) you were talking about and removed it. That solved the problem. Of course, while dealing with the frustration of finding a solution to this. I managed to get 10.7.2 working, which I hadn't been able to do before. Sheer stubbornness this time. When THAT didn't fix the problem, I wanted to break something. Fortunately I ran across the plist you mentioned in a search.
So, in summary, thanks for the help! Next time I'll pay better attention.