im running both norton antiv. and firewall..I disabled the xp sp2 firewall/antivirus (which is sponsored thru avg) and just continued to use my norton.
was totally slowing all phases of my comp till I disabled both of these in my control panel, and now it runs better. it's going to slow down your comp, alittle bit, in the boot up process, and in general while programs load into memory..but now I disabled those 2 things, it's back to normal for the most part, just noticing a slight slow down now.
this is no longer a beta version, so this it folks..unless microsoft decides to change something, which dont count on it, because many people had probs with sp1 when it came out...so yeah, microsoft will release periodic updates, especially when new/big virus threats come out..but the main sp2, is pretty gonna stay the way it is.
Definately dont run the sp2 firewall/antivirus if you already have one installed, dont need it, and it doesnt really offer more protection since norton is good enough on its own..now if you're running a router, than thats even better of course.