I'm pleased to say that as expected, I don't have it. I'm not a big fan of this "anti-piracy" rubbish (in it's current form) and so I don't put such stuff on my computer if I can help it. (in much the same way as my HJT log is consistantly quite clean, certainly with no serious nasties - just unesssecary annoyances now and then

)
In terms of uninstalling Norton/symantec, I'd recommend that to ANYONE. You'll quite possibly notice a marked increase in the speed of your computer once you do.
In terms of firewalls conflicting, good question. I just know that they do. The only way I can imagine it (never thought about it before) is that a firewall is a gate on the road into your system. Imagine if you will that the firewall rules are a sentryman on top of the gatetower that decides what can pass through the gate and what can't. By installing a second firewall you are infact putting two sentrymen on top ogf that gate tower, and both have different methods. As a result, they may sometimes disagree on whether they should let something through the gate, or if they both agree that something should pass through, they may both stand on top of the gatetower arguing about why it should be allowed instead of letting it through.
I must say, that this is a complete guess. As I said, I've never thought about it before, but that's the only way I can visualise it and explain it without some research on the subject.