Problem: Have a router in Orion. Say you have a MPLS T1 connection monitored. Then you upgrade it to DS3. Tech takes out T1 card, adds in DS3 card.
If you don't remove the T1 interface in monitoring before you remove it, you're toast.
When you rescan the resources, Orion still shows an interface alarm on old T1 interface... even though it's not there anymore. 
"Solution" from support is to delete the device and re-add it. Annoying, as there goes your history.