[cvsnt] WinCVS - ssh checkout at Sourceforge does not work

[Bavarian]

The configuration I am using:
    - WinXP SP2
    - Siemens SX541 router  (open ports: 20, 21, 21, 2400, 2401)
    - WinCVS 2.0.2.4

My Problem:
I am trying with 
CVSROOT::ssh:myusername at cvs-ssh.sourceforge.net:443:/cvsroot/mediaportal in 
WinCVS to check out the sources. I input my password  and thats it - no 
further reaction from WinCVS beside the fishes in the lower left corner. 
They are going up and down, up and down, up....

How can I found out what is wrong?

Manfred