I'm using McAfee too, but it haven't given me too much trouble, yet. The random scans have all come at convenient times so far.

I had F-Secure anti virus on my last laptop, though. But it didn't have an internet connection at that time, and it kept whining it needed to update every time I turned it on. Grr. And when I did get a connection it blocked all sites with bad words in them (like Kyono & Rye's LJ), that stupid little babysitter. And my password was 500 miles away, so yeah. Luckily my mom found it. What a whore. (The anti-virus, not my mom.)