asterisk users - Dec 2005 - transfers from Polycom 501 involving Sipura 300 and asterisk 1.2

When transferring a call that came in on the Sipura and picked up by a
Polycom 501 (sip 1.52), then transferred to another polycom using the
transfer button on the polycom (havn't tried with the blind transfer
from the polycom phone), then as soon as the transfer is complete
(after pressing transfer again on the polycom) then the caller on the
Sipura side can hear the new polycom caller, but the polycom cannot
hear the sipura caller. This is all on a flat network, no nat, no
gateways, between any of the points. If I change canreinvite=no for
the sipura then everyting works fine.

I'm assuming this is a bug in 1.2, but before I jump to conclusions I
would like to know if anyone else has seen this?

I did not yet have a chance to capture the output, but will do so if needed.

Thank You