[Paraview] Why the client can not be started?

[nancy]

Hi, all,
      I  am learning  to use Paraview for visualization of some data, and just download the version 2.0.1.
But when I test the Client/Server mode on two PCs, one of which is installed windows2000 and another is windowsXP,  the server is started normally, but the client can not be started. The commandline is as:

On B I type:
       pvserver -ch=[IP or name of  A]
       Listen on port: 11111
       Waiting for client...

On A I type:
       pvclient -sh=[IP or name of  B]

the process of  pvclient is exist, but no response appears on B or A.

While, if I start server and client on the same machine, everything is OK.

Is there anything wrong with my operation? who can help me?

Nancy