using FXP in IPv6

I installed a FileZilla server on 2 different VPC (Win7 and Windows Server 2008).
FXP block options are unchecked in FileZilla server.
Firewalls are all turned off.

My client is a third Win7 VPC using SmartFTP to create a connection to the 2 VPC mentioned above.
I tested FXP in IPv4 to make sure connection and port opening were working correctly.
However, the same test performed on IPv6 failed.

Has anyone use FXP in IPv6 environment successfully who can help me?