good points Nagan
It appears that the scan of running processes on first access is what's taking the t-timer-time
As opposed to a system wide scan I do not kow how you can do any useful work till the system is secure
I have confidence in Spybot team getting a grip on this

have you had any issues with sd-helper as others have reported.

I mentioned AV as there have been several posts about alleged interference with AVG 8 or AVG8 anti-spyware additions. I'v seen no such reports for Avast or Antivir