When setting up the CFA on the IPPhone the phone updates the publisher DB real-time, or attempt to. I the phone is registered tot he Sub & there are communication issues between the Sub & the Pub then the phone will not be able to se the CFA. I assume that your phones are registered to a Sub. If you register the phones to the Pub can you ser CFA from the phone?
Enable Detailed CCM & Detailed DBL traces in the CCM's then try a CFA from the phone. After the failure go to the traces & look for errors. It could be something a simple as DBL needs to be restarted or the service passords need to be synced.
Mike
