When you transfer responsibility of a ticket to another person, the other person will show as CN=Hans Holt/O=Convergens and the lookup of the telephone number fails.
I have added the following code to make up for the problem:
picklistback = FetchSupporter(Wksp,DB,MessageslistitemNotExists(messageslist, "msgTicketDSelSupporter",2))
If Isempty(picklistback) Then<br/>
Exit Sub<br/>
End If<br/>
' selected a supporter go on and change the document<br/>
' NEW CODE
Evalstring = |@Name([Abbreviate];"| + picklistback(0) + |")|<br/>
picklistback = CheckAndEvaluate(Evalstring)<br/>
'*** END of NEW CODE