Did your computer meet Spy Spweeper's requirements? I'm a Spy Sweeper user (little more than three years) and I have never had this issue. When it updates, it takes up a lot of resources, agreed, but this every ten minutes thing has me wondering. I don't even know Spy Sweeper is on the machine unless it's updating or has a security breach. I've seen Spy Sweeper on numerous other systems as well without any issues.
As far as leaving Spy Sweeper, I have always heard good things about AVG Anti-Spyware (Formerly known as Ewido Anti-Spyware). Have a look at this page
. It has the real time protection, which I expect to work very similarly to Spy Sweeper's.
On another note, you should always consult a Geeks to Go! Malware Specialist first, as they know the ins and outs of internet-borne nasties. I'm going to assume that you overlooked this pinned topic inside this Applications board... Free Antivirus and Antispyware Software, Includes screenshots and recommendations by admin.
Hope this helps in some way.