Your problem with Mcaffe, is that 4.5 is only version that is meant to be used with Windows 2000. Trouble is, it about halves the performance of your PC.
I have a couple of people checking with the software developers to see if there is any possible solution.
The offical NAI respsonse was (and I quote)
"disable email scanning and internet download scanning"
Erm... Don't think so somehow. So their product went in the bin, and in came a nice shiney copy of Norton AntiVirus 2000 which runs flawlessly.
I also have the Lanman problem, so thanks for the hint for that.