I have a similar problem to someone else after upgrading to 10.1.3.

I discover and deploy to workstation A. That goes fine workstation A registers and is where it should be. Now I discover and deploy to workstation B. This removes workstation A including name and everything but now B is there. I go back to machine A and zac unr and then re-register and now workstation B is removed and workstation A is there??? What in the heck is going on this is soooo frustrating. I have completely blown away one of the machines and rebuilt it from scratch not an image and removed every trace of ZENworks off of the other and this is still happening.

Both workstations are XP sp2 and ZCM is installed on Win2k3 box. I deployed to 90 workstations and it worked perfect but now this craps happening after the update!!