Voice Call PC2PC on 2.5.8 or 2.6.0-dev2

Installing version 2.6.0-dev2 from full EXE file on XP and/or Vista presents the option of voice call, but no call is possible…

Sniffing the packets, I see that B-side is canceling call with “feature-not-implemented” with body <xmlns=“urn:ietf:params:xml:ns:xmpp-stanzas”>.

After this error, if uninstall 2.6.0-dev2 and install 2.5.8, same error occurs.

How to make it work? Wich version supports this feature on XP and Vista environment???

Thanks in advance

Edson.