I am having the same problem: when using a SOCKS 5 proxy server, WinSCP uploads files truncated to any FTP server. If I disable the SOCKS 5 proxy, no more truncation occurs. The proxy server is a local proxy that is set up with MyEnTunnel, which is actually just a GUI front-end for Putty's plink. I'm using the latest version of WinSCP (4.2.5).
Only files bigger than a certain number of bytes seem affected. Some testing revealed that this threshold lies somewhere between 500 and 600 KB.
Because the issue also occurs with FileZilla, I am starting to suspect that this isn't a bug in WinSCP, but a problem with the SSH server or a bug in plink.
Only files bigger than a certain number of bytes seem affected. Some testing revealed that this threshold lies somewhere between 500 and 600 KB.
Because the issue also occurs with FileZilla, I am starting to suspect that this isn't a bug in WinSCP, but a problem with the SSH server or a bug in plink.