I've tried a commercial client sucessfully on my campus (humm.. I dont remember the name) ...can this be a bug in putty/winscp !?
I don't think it is a bug of WinSCP and it cannot be a bug of Putty. What commercial client does work? Are you sure it was SCP client? It might have been SFTP client. There are usually less problems with server configuration for SFTP than for SCP. WinSCP is going to support SFTP with next release.