hi -  i have a windows xp and when i installed norton 360, i also started seeing the suspicious cloud warning every time i turned my pc on.  i also started having problems on start up with the sonic update manager. it would continually try to run even tho i would try and cancel it out.  i am not computer smart by any means, and most of the answers to resolve issues on this forum are way over my head.  i did get tired of fighting the sonic update manager, and went to the add/remove programs and just uninstalled it.  didnt cause any other problems, and also the suspicious cloud was gone.  its been about a month now and still the problem is resolved.  hope this might help you....