I have a CUCM 6.1 cluster whit 200 phones and i have the follow configuration:
CUCM Group: Stgo
Device Pool: Stgo
-CUCM group: Stgo
And all endpoint have the same Device Pool (Stgo) and the same MRGL (MRGL_Stgo), and one time at week user can not make transfer and conference and when restart the service Cisco IP Voice Media Streaming App the problems it's OK.
And look the log at publisher and have this log:
MtpNoMoreResourcesAvailable: ID Publisher.