Cisco Firewall :: ASA 5510 - FTPS Explicit Client Fails At Init TLS Stage

I have a problem when trying to access from a workstation on the internal network to an external FTP server using Explicit FTPS. After the server requires the client TLS Authentication the client inits TLS but the connection is closed by timeout.
 
I have disabled the FTP inspection on the firewall and I have opened some high ports from the Internet to the test workstation (ACL and NAT rules), but without results.
 
If I try to connect from a workstation to the FTP server using a direct Internet connection I can access the FTP server without problems, so I think the problem is in the ASA.