Windows 8 Scans Not Starting Re-occurs Days After Uninstall/Reinstt

I uninstalled & reinstalled on 3-17-2012. Ran a full system scan successfully.  But here is is 4 days later. No other scans have been automatically started by NIS. Liveupdate occurs daily. AND now manual scans are back to the same song & dance of not starting.

 

Essentially, It seems that if I want to scan my computer I have to uninstall & reinstall every time to accomplish the task!!

 

Something is wrong here. I'm confused about what to do. Any help would be appreciated.