I am not sure, perhaps I have found a bug.
Putty always shows me the real "changed" time of a file.
But winscp shows me the real "changed" time + 1 hour.
I am using Winscp 3.7.5 on a Windows XP Computer, and I am connected to a Solaris 5.8 Server
I am just a User with no experience in bug-reporting. If I am not right, just delete the post :-)