The slash is correct (assuming the account it chrooted).
Can you upload a file in WinSCP GUI? If you can, can you post a complete session log file showing that?
Thanks for your reply. I was able to retest the code late in the day yesterday when a new file came in and I got it to work. the "/" was correct, as you said, in the first place. I'm still not sure yet why it failed before but it seems I'm good to go now. Thanks again.