Communicator Presence not correct in Outlook

[TomK]

We're seeing some users showing up in the Outlook From/To/CC fields with
incorrect presence. To be precise the presence is "unknown", but if you go
into Communicator and look at the user their presence is accurate
(available, busy, etc.). In addition it's not all users. Some users'
presence is correct.

Our environment:
Outlook 2007 SP2, fully patched Exchange 2007, Communicator 2007 R2 (server
and client) both fully patched.

Anyone seen this before?

Thanks,

Tom