This is happening to me also. I have several blogs and this happens to the ones I upgraded and added Bunny Tags to. I used to think there was something fishy about Bunnny Tags which I installed the same day, but once you take all the bunny tag stuff out, nada.
The day I installed Bunny Tags is the same day Technorati stopped reading my pings. I can’t remember if I also upgraded the sites to 2.0.2 the same day however.
It is NOT my server because the other WP blogs (all on a shared server) still ping to Technorati fine.
The blogs in question are…
https://towncalleddobson.com – WordPress 2.0.2
https://ifthisbetreason.com – WordPress 2.0.3
The blogs that seem ok (never had Bunny tags)
https://rallybadge.com – WordPress 2.0.2
https://allthingssekhmet.com/ – WordPress 2.0.2
I might also note, I just upgraded IfThisBeTreason.com to 2.0.3 to try to reawaken Technorati to no avail. But now my dates are screwed up.