DW 9 Synchronization Issue with Remote

I have a site that is has all it's administrators and contributors
using DW9 and check-in/check-out disabled. Instead the admins
synchronize the site to a network drive pretty often for back-up
purposes.

Very frequently, DW will show files which it marks as modified, but
they have identical content and perhaps different time-stamps.

Can anyone help me guess why?

I thought DW 9 had the time-zone issue fixed.