We were having a terrible time with our install of Whats Up Gold v12.4.  Everything seemed fine but then our polling service seemed to stop and adding new devices just stuck in an unknown state.  The only way to rectify this was to stop and then kill the NMService.

Stuck with Support trying to resolve our issue and after a few attempts BOOM!!! Fixed, we seem to now be running on all cylinders!!

I have noticed a few people on here having the same issue and ours was resolved because of an Active Script monitor that was basically taking up all the resources of the outgoing and running tasks within Whats Up Gold, as soon as this monitor was disabled all was well.  Therefore my suggestion and I can imagine supports suggestion is check your Active Script Monitors and also use the Whats Up Gold Engine perfmon counters to check for any issues.

Once again thank you Support and Will, you have made my life at work alot easier!!!