I'm not real sure what you mean by your users are assigned to the opening greeting... you don't assign users to handlers like that. The opening greeting can have one owner and one recipient (usually the same user...) but you can't have multiple subscribers linked to a call handler. Unless I'm misunderstanding you here?
Primary call handlers are hidden... each subscriber is made up of two part: Their exchange email account (of course) and a primary call handler which stores their extension, transfer numbers, on key dialing, greeting etc... these have most of the same components as regular call handlers but they are hidden (i.e. they don't show up in the SA in the call handlers pages).
The user deletion process first looks for this primary call handler and tried to delete it... if it can't find one or there's something not right about it, I'm guessing the deletion process is failing entirely and it just jumps out. This is pretty unusual, but someone in support should be able to quickly help you out using DOHPropTest to get "under the covers" and check out what's wrong (I'm kind of curious to know what state the primary call handler is in or if it exists at all.)
Jeff Lindborg
Unity Product Architect
Cisco Systems
jlindborg@activevoice.com
http://members.home.net/jlindborg
