I did a clean reinstall of OS X 10.6.8 and was immediately stymied by being unable to connect to the Internet.
After my head-scratching degenerated to angst, though, I had a brainstorm, went looking, and found that importing my network settings had left me with the DNSCrypt DNS server numbers in place, and they were, of course, useless before DNSC was reinstalled.
I hope nobody gets stuck having to reinstall, but if you do, keep this in mind, and either make a note of the Open DNS server numbers or reinstall DNSC forthwith.