550 Security server forbids STOR before PORT/PASV !??

[Alexander Holzer]

I have a problem with checkpoint firewall-1 (FTP) by upload and download.

Authentication - OK.
...
TCP PRINT hSocket, "TYPE I" <-- Ok
...
TCP PRINT hSocket, "PASV" <-- Ok
...
TCP OPEN PORT ... AT ... AS hSocket <-- open data port on Firewall, Ok
...
TCP PRINT hSocket, "STOR " + remoteFile <-- Firewall blocked this command with
550 Security server forbids STOR before PORT/PASV.


I have no problem with ftp-proxy servers. Data communication (upload/download) works fine.

Is this false command sequence for checkpoint firewall-1?
Where is mistake in this procedure?

Thanks

[Alexander Holzer]

The problem is solved!
WSAStartUp() - WSACleanUp

TCP OPEN ... opening of TCP port/services does not provide synchronous process of performance of procedures. ..from personal experience