You can do a search here to get an extensive earful on what a bad program Norton Utilities is and has been ever since Symantec got hold of it, so I'll not recap that.

I don't have any opinion on Sophos, though I consider it completely unnecessary and, like Norton, a resource and speed-sucking add-on that does nothing.

But the point I was trying to make is that having two anti-"virus" programs running at the same time is likely to create its own problems, just as having two firewalls on causes problems rather than making you "twice as safe."

This is not a PC; it's a Mac. It's not the same, and should be treated as the same.