I had a somewhat similar situation when I found out that (at least on WinXP) commiting a folder rewrites all files in it, including those that were present before entering shadow mode. I tried to commit my downloads-folder (around 40GB), after downloading one 10mb file. So, in this case the commit function is not feasible, you have to commit the new file itself (unless it's 350gb, that is ). Well, since it was a system for testing SD anyway, i pressed "pause" and rebooted, just to see what would happen To my amazement, there were no corrupt files (except that the new, recently downloaded file was non-existant, as I expected). Also, the timestamp on the last successfully commited file showed the time of commiting, (both the "created" and "last modified" timestamps), not the original timestamp. Those do get preserved after successfully commiting files. So it seems that SD first copies the file to the "real" system, and then sets the timestamp.