I also have "SpySweeper" running with 12 shields active.
Are you referring to avast having 12 shields active ?
If so, avast 4 Home only has 7 providers (shields) and usually there are only 6 running (outlook/exchange is usually not running), so you would appear to have duplication and a failed installation.
Try a repair of avast. Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow. You need to be on-line to do this.
If that doesn't work try, uninstall, reboot, install, reboot.