need an opinion on Internet security software

I would like to solicit opinions on Internet security software.

Currently (and for the past 4 years) I am running BitDefender Internet Security 2010 and have recommended and installed it on many of my clients machines (95% running XP). Over the last 3 months I seem to be encountering more problems with the program than I think I should have. Things like warning that the computer has not been scanned when it has been doing so for several weeks. Parental controls that do not allow a user to make changes. Update service not working. Critical error (that is never explained) shutting down the program.

It also seems to take up a disproportionate amount of system resources now which is not how it used to work. It was really quite good before.

The 2009 version worked fine - hardly ever had to attend to an issue but 2010 is not living up to expectations.

Their support is virtually non-existent. If you contact them they will ask that you send in details and a file from within the program but I rarely hear back from them as to what the issue is. When I do get a response it suggests that I shut down all of the BD services and see if the problem happens again. I don't have time to waste debugging their software.

A bit of a rant however, there must be dependable products out there that fellow forum members could advise me on.

Might make a good topic for a forum survey

Thanks in advance to all who answer