I have successfully configured nokia e52 with asterisk 1.8 using TLS/SRTP.
Everything is fine except the incoming calls - no ringing at all. I can make encrypted outgoing calls from the nokia ( when I am using plain SIP the both directions are fine ).
I already checked with other TLS/SRTP capable device, if the problem exist on asterisk side - but seems is OK - the other device make and receive encrypted calls.
In the latest SIP error messages I can see: