Spybot-SD updates every week, so you wouldn't be seeing any updates if you've updated last Wednesday. Just because the scan "slows" down on the Zlob. entry does not necessarily mean that you have it on the computer.
Are you running any other scans during a Spybot-SD scan? Do you have any other programs active?
I would suggest you run it (Spybot scan) when the computer is at minimal activity.
Can you run the scan in 'Safe Mode' to see if this corrects the probelem?
Also, have you cleared the cache and cookies from your browsers?
How about the Temp. files on the computer?