SSL - Server Certificate

I imported my CA certificate into my Windows 2000 workstation. It looks fine when I display it. When I try to connect to my mainframe FTP server, I receive:

220 Connection will not timeout.
AUTH SSL
234 Security environment established - ready for negotiation
Connected. Exchanging encryption keys...
SSL Error
The operation completed successfully.
Connection closed.

I get this message whether my certificate is installed in my workstation or not. Any ideas ? I pursued the error in the FTP Server on the mainframe side and they indicate that the client is closing the session. Thanks.