[asterisk-users] half channel audio after upgrade to 1.4.18

[Jerry Geis]

I upgraded from 1.2 to 1.4.18

After upgrading I get half channel audio on SOME phones.

I have Cisco 7960 that works, I have a wireless polycom 8002 phone that 
works.
However, my polycom 501's are getting half channel audio on EXTERNAL calls.
Internal calls are OK.

I have enabled nat=yes on all phones.

What is something else I can try? Any thoughts on why half channel audio 
after the upgrade?

Thanks,

Jerry