Now there seems to be a bit of confusion about the NPC server. From my observation, the NPC server hasn't gone down in 3 weeks or more. What it appears to me to be is that when an NPC is attacked, it will randomly lock up and become impervious to attack. This looks like it happens on a per monster basis. Eventually every monster gets locked up through this process. I think this would be different then the npc server going down. If the NPC server crashed, we wouldn't be able to talk to the npc's. Now this is all speculation and a comment from a dev would be nice. With that said, it does play right into my suggestion of periodically reinitializing the both Servers (refering to server software). This again assumes that shuting down the programs and restarting them would actually solve the problem. It might more like a data field becoming corrupt. But I'm sure the devs have a pretty god insight into the issue. Knowing the path, and walking the path are 2 very different things.
Regards,
Elois