Hi Morgan,
This is normal, if you are using most voicemail systems including Unity or Avaya voicemail this is working as expected. The problem lies in the fact that Unity sees the First Redirecting or Originally Dialed number (User A's CLID rather than the Last Redirecting Number (User B's).
There is a fix in recently released Unity 5.0 though :)
Have a look at Michael's great posts, there is a fix on the horizon for this exact problem in (Unity 5.0) **now released,(ECSBU Test Engineer, CISCO SYSTEMS )
"The situation you describe here (getting Unity to recognize the last forwarding station rather than the first forwarding station), will be a system-wide option added to Unity 5.0. There is not a way to do this with a configuration setting on earlier versions of Unity. I'm not aware of any CallManager settings that will address this issue either."
"We use the OriginalCalledParty and OriginalCdpnRedirectReason fields in SCCP StationCallInfo message from CallManager. The feature in Unity 5.0 will allow admin to configure Unity to look at LastRedirectingParty and LastRedirectingReason fields instead, on a system-wide basis."
From this recent thread;
http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=IP%20Communications%20and%20Video&topic=Unified%20Communications&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.1ddada58
Also, here is another reference to this exact question with an answer from THE Unity Guru Jeff Lindborg;
http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Unified%20Communications%20and%20Video&topic=Unified%20Communications%20Applications&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.1dda8a86/0#selected_message
If this is just a one-up type of setup you can configure a Voicemail profile (in CCM) for User B and apply it to User A that will allow this type of Call Forward to User B's mailbox.
Or in Unity set up Alternate Extensions so that User A is an Alternate Extension for User B etc. Sharing a Cisco Unity Voice Mail Box between Two or More IP Phones
Configure Alternate Extensions
Open the Unity System Administrator web page.
Navigate to the subscriber's profile. Select Subscribers > Find and Select a Subscriber > Enter Subscriber Information then click Find and click the Subscriber's name for the subscriber that owns the primary phone (Phone B).
When the subscriber page comes up, select the Alternate Extensions option and click Add.
Enter the alternate extension number (in this case Phone A) and click the Save icon.
From this good Unity doc;
http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_configuration_example09186a008015ceec.shtml#steps
Hope this helps!
Rob
PS. I did post an answer to the PIN issue you were looking for the other day.
