William,

Check out this doc about behavior with Phone View/Message Monitor and failover:

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_tech_note09186a0080883f88.shtml#detdevice

By default, the device list is retrieved on a Cisco Unity restart. This also occurs on a regular 15-minute interval. The device retrieval occurs for the first Cisco CallManager server listed for each integration on the Unity server. If the first (primary) Cisco CallManager cannot be contacted, we try the next Cisco CallManager listed on the integration (if there is one), then the third, and so on until we get the information successfully or all fail. In a Cisco Unity failover pair, the failover server does not retrieve the device list until it it is active. While the failover server is active, the primary server does not get the device list. This can result in a temporary Phone View outage within a Cisco Unity failover/failback event.

The only thing I can think of is that I would give it some time, maybe you'll see a difference in behavior once the default 15 mins passes and the device list is retrieved?

Hope that helps,

Brad