I see that Norton in the 2009 version is getting some good reviews it was right at the top in the most recent avcomparatives testing also at dslreports and virtualdr. I have been using it on two rigs myself one since early beta and one an upgrade from 2008 and so far zero problems and the speed and low resource requirements are impressive. If you have not tried Norton in a while and you are willing to have an open mind, give it a look there is a 15 day free trial available. Disclaimer:I do not work for or have any association with Symantec, I am just pleased to see an American company step up to a higher level and provide another viable option for security software.
Amos
Amos