It is using SFTP(v3)
No, I was wrong. I noticed that the dates and times are the same, but the sizes shown in the left/right file panels are different. BUT, this is VERY strange because I (1) created the local files on the USB-removable hard drive by using WinSCP to connect within my LAN (intranet) to copy the files from RH9 to a Windows 2003 NTFS-formatted USB-removable hard drive using SFTP protocol, (2) unmounted the USB-removable hard drive from Windows 2003 and connected it to the USB of a WinXP system that was on an internet remote (different ADSL line) from my intranet LAN, (3) used WinSCP on the WinXP in SFTP protocol to remotely connect to the same RH9 that was the original source of the files on the USB-removable hard drive, (4) tried a synchronization. Why would the dates and times be the same, but the file sizes be different? The physical disk is the same USB-removable hard drive on both systems.
Is there a way to send you screenshots?
What protocol are you using, SCP or SFTP?
Are the dates and sizes showns in file panels the same too?
When you allow WinSCP to overwrite the file, does the date/size of the local file change?