Instant message or call is directed to a wrong contact in Lync 2010

Consider the following scenario:

• You create a contact card for a user (user A) in Microsoft Outlook.
• User A’s email address or telephone number is changed to the email address or telephone number of another user (user B) in the contact card in Outlook.
• You perform a search for user A in Microsoft Lync 2010. 
• You try to start a conversation with user A by sending an instant message.

In this scenario, user B receives the instant message unexpectedly. However, in user B’s conversation window, the sender is user A.

Note This issue may also occur when you try to make a call or send an email message to user A by using Lync 2010. In this situation, user B may receive the email message and see user A as the sender.