OK, reading your message carefully again...
SCP protocol is not reliable regarding timestamps. It is hardly possible to make it work consistently with SFTP (which hopefully is reliable as it is implemented in WinSCP). More over Windows 7 changed a way timestamps are shifted when DST in turned on or off. The latest released version of WinSCP does not account for that yet. The next one will. So either stick with SCP for now. Or if you want to switch to SFTP, do, but perform timestamp synchronization.
SCP protocol is not reliable regarding timestamps. It is hardly possible to make it work consistently with SFTP (which hopefully is reliable as it is implemented in WinSCP). More over Windows 7 changed a way timestamps are shifted when DST in turned on or off. The latest released version of WinSCP does not account for that yet. The next one will. So either stick with SCP for now. Or if you want to switch to SFTP, do, but perform timestamp synchronization.