Lync User Contact Information

We have a single Lync 2010 server. All users have there AD telephone numbers set as +61 2 9123 xxxx. We are using RCC. On the Lync client when USER A checks the contact card of USER C he see's the work number as  xxxx.When User B checks the contact card of User C he see's the phone number as +61 2 9123 xxxx . Why is this happening

Malli Boppe MCITP Enterprise Messaging Exchange 2010