libvirt users - Aug 2012 - virDomainMigrate() leads to SASL error

Hello,

I'm trying to use virDomainMigrate() function through libvirt-php but
I have this error coming from libvirt (this is an error raised by
virDomainMigrate(), not by php binding) :

Failed to step SASL negotiation: -7 (SASL(-7): invalid parameter
supplied: Unexpectedly missing a prompt result)


My two connections are over TCP with login/password provided (URL is
qemu+tcp://X.X.X.X/system)
Connection to both hosts independently is working (listing domains, etc.)
Migration through virsh is working too !

On destination host, I have this in log file :
2012-08-09 14:29:23.628+0000: 17179: error : virNetSocketReadWire:1003
: End of file while reading data: Input/output error


Can someone tell me if I'm doing anything wrong ?

Thanks !

Olivier