amigadave wrote:
I use a firewall and up to date virus protection
That might be the problem. I have always found antivirus programs (especially McAfee and Norton) to be enormous lagging b*tches. The only protection I have on my current pc is the standard XP firewall, and no antivirus, and it has a quite reasonable speed (XP 2000+ with 256MB and WinXP/SP2).
My opinion is that when you only open trusted (and then I mean REALLY) trusted files, there's not much to be scared of. The only extra protection that I have is a monthly run of my spyware-eraser.