Problems opening several programs with NIS 2011

Installed NIS 2011 a few days ago, and having some problems getting several programs to work the way they did before. Both worked fine before NIS 2011, using N360 2010, and both work fine when I uninstall NIS 2011, but obviously that's not really a viable solution long-term every time I want to use these two programs.

 

Which are;

 

1) iTunes. The only way I can get this to open is to open it the second the desktop appears - i.e. before NIS has properly woken up. Any later and it just won't open at all. I also have to turn off the firewall to make any purchases.

 

2) Windows Live Mail. Not only is one of the two email accounts I have linked to this being blocked, but opening this program causes Norton and Firefox to become unresponsive, and I have to reset the whole machine. Somehow I did manage to get it working properly once - by going into the Network settings and turning off the email virus scan - but that's not working any more.

 

Anyone else had these problems?