The message "Skipping busy (err 32)" log source file, is telling us that some process, most likely the ProxySG but it could also be something like an anti virus engine, has the file open and as a result Reporter is unable to process the file at that time. If this is the case Reporter will eventually try to process the file the next time it scans the log source by which time the file should be released by the process that had it open. This may depend on how frequently Reporter is setup to scan for new files.
The error is typically seen on a busy Reporter server or on a server where IO and/or networking is slow.
The actual error code is an FTP error indicating a 'broken pipe' or connection, this can be misleading as if it truly where a broken pipe Reporter would not be able to go on to process more files for the given log source.
To resolve this it is important to confirm if the connection has truly been broken or if something has the file open.
Make sure the server is not running an anti virus engine against the files