why does robocopy say this file is older?
Solution 1:
I had the same issue and came across the following:
http://www.conetrix.com/Blog/post/Robocopy-Incorrectly-Detects-Files-as-Newer-When-Copying-Between-Different-File-Systems.aspx
Basically, this indicates that you can use the /FFT switch to Assume FAT File Times (2-second date/time granularity).
Using this now and I no longer get 100000 identical files overwritten