I seem to be having trouble with my installation of Wordpress sending out pings to other sites, and also using the Ping-o-matic and Technorati RPC service.
This is becoming a nuisance, as every time I post (which has been becoming gradually more frequent lately), I have to manually ping Technorati.
I have refrained from using other blog [...]

Just as I finish updating my version of Wordpress – another one comes along!
Although a bit of a nuisance, I security on your blog is never a bad thing!