it only started after the recent update from microsoft was installed by me. i don't know when the package release was but i know it was a recent update i installed. after that is when svchost.exe started eating up my CPU.
I have this vague recollection that one of the Windows updates was intended to fix a vulnerability in this or a related process. I can't help wondering that if by fixing it (or trying to) something that was exploiting it had a hissy fit on your system.
It certainly isn't normal behaviour, and although being forced to turn off Windows Update might send a geek or two somewhere into ecstasy, it isn't a good thing in the long run.