I use AVG - same as several others in our MP group.
Firewall
Checked through this with MTG the other day. No problem that we could see.
Programs either auto-updating or scanning or checking in the background
Using CCleaner have eliminated all non-essential Windows and other apps from start-up. And wouldn't they effect SP as well?
Router
Using a Virgin Superhub, which is not great at wireless, but I'm cabled in so that's not an issue. I get very stable download of 40-50 meg to the PC, and upload of over over 6 meg. Also very low jitter.
ISP
Virgin, who are one of the top 3 in the UK
Any other activity on your IP address (other users in your home)
Occasionally, but not during the last 3 MP games.
Malware
I've run Panda and Trend Micro online scans, and also scans in safe mode using AVG and Spybot.
Keep those suggestions coming folks
