I have exactly the same problem as Negeltu... and what's even worse, it's not just
Network shiled that's affected, but also
P2P shield and
Instant Messaging...

I started those providers prior to rebooting my system... every single time I log back on to Windows, providers are terminated, and only my STANDARD shield, Internet mail and Script Blocking are started and running...
Ah, yes... latest build here: Nov2004 (4.5.495)
Any idea on how to fix this, would be greatly appreciated.
Cheers !