Hi Thom,

This is a question that all of us have pondered at one time or another. It must be stressed that the balance between Privacy and Call coverage is tough with all CCM versions until CCM 5.X

Unfortunately when you use Shared Lines with CCM versions before 5.x this is expected behaviour :( This is one of the biggest drawbacks of using Shared Lines (all call details are passed along with each call).On CCM the feature you want BLF (Busy Lamp Field)is not available until CCM 5.0(1). This is a feature that was much requested on releases leading up to 5.0 Have a look at the following link. Here is an excerpt;

When you configure Presence in Cisco CallManager Administration, an interested party, known as a watcher, can monitor the real-time status of a directory number or SIP URI, a presence entity, from the device of the watcher.

A watcher can monitor the status of the presence entity (also called presentity) with the following options:

BLF/SpeedDial buttons

Missed call, placed call, or received call lists in the directories window

A Phone Monitors a BLF/SpeedDial.

After an administrator configures the presence feature and the BLF/SpeedDial buttons, a user can immediately begin to monitor the real-time status of a presence entity.

From this CCM 5.0(1) doc;

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_administration_guide_chapter09186a008053189a.html#wp1098807

Until CCM 5 the best you can do is configure the "shared lines" you want for multiple users and live with the Call Details :(

Hope this helps!

Rob