[Asterisk-Users] Transposed ringing

[Trevor Peirce]

I don't suppose anyone might know why I hear ringing transposed over 
itself when I place a call out via PRI?

SIP to SIP is fine
SIP to IAX is fine
SIP to PRI is always transposed

I mean sometimes you don't notice it much because it's lined up right, 
but other times you'll hear a really long ring (starts sounding normal, 
then sounds "weird" -- like two rings played at the same time, then 
sound normal) or quick choppy rings.  It seems very much like there is a 
ring from the PRI and another ring from asterisk or the Sipura phones & 
ATAs.

Any clues would be appreciated.

Trevor