Presentation Manager is constantly accessing the hard drive to load images and movies ...
The software may access the internet if requesting RSS feeds. Certain settings on anti-virus packages
check for this type of activity and, consequently, conflict with PM.
NOTE with Norton you need to disable heuristic scanning / remove heuristic threat.
Software providers claim heuristic technologies can find viruses that have previously been unknown,
and yet to be discovered and added to virus definition files. Norton's heuristics reject many good
files.