Microsoft peer web services question

An interesting anomaly has come up in the following scenario, does anyone know whether this is Peer web related? or does anyone have any suggestions as to where else we may look for a solution.

We have 50 remote sites, all using NT workstation 4.0. Some use the Peer Web Services link to ftp sessions to p****information back and forwards between the PC and a Mainframe.

We appear to be getting incomplete files from the Mainframe, and then about two minutes later the correct complete file arrives.

My first assumption is that we are losing the link temporarily with the Mainframe, this is picked up, and the file is resent, but Peer Web Services effectively starts a new file rather than overwriting the incomplete file. Am I correct?

Is there a way to configure Peer Web Services to overwrite a duplicated or incomplete file, or do we need to negotiate with the Mainframe suppliers to come up with a solution?

Thanks

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