Hi Scott,

Is this problem with all phones or just the ones not configured with the dual-line command? My guess is that adding the dual-line to all ephones will resolve the problem.

A dual-line ephone-dn has one virtual voice port and two channels to handle two independent calls. This capacity allows call waiting, call transfer, and conference functions within a single ephone-dn. Dual-line mode is supported on all phone types, but is not appropriate for voice-mail numbers, intercoms, or ephone-dns used for message-waiting indicators, paging, loopback, or hunt groups. Overlays of single-line hunt groups onto dual-line buttons are supported.

Ephone-dns are created in single-line mode if the dual-line keyword is not used. Changing an ephone-dn from dual-line mode to single-line mode (and vice versa) requires that you delete the ephone-dn and then recreate it.

Examples

The following example enters ephone-dn configuration mode to create the ephone-dn 5576:

Router(config)# ephone-dn 1

Router(config-ephone-dn)# number 5576

Router(config-ephone-dn)# exit

The following example creates an ephone-dn with the number 1001 in dual-line mode. The no huntstop command allows calls to continue to hunt to other ephone-dns if this one is busy or does not answer. The huntstop channel command disables call hunting to the second channel of this ephone-dn if the first channel is busy or does not answer.

Router(config)# ephone-dn 10 dual-line

Router(config-ephone-dn)# number 1001

Router(config-ephone-dn)# no huntstop

Router(config-ephone-dn)# huntstop channel

Router(config-ephone-dn)# exit

From this good CME doc;

http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_command_reference_chapter09186a0080611350.html

Hope this helps!

Rob