ver 8.2.2.5 U
I spent a full day updating 867 HTML files, losing several. So I did usual
"update [copy].. if newer" and had OLD copies destroy all new copies.
Undo could not handle the list. Reboot did not help. Re-install that tool did not help. What is going on and what is the fix.
My RSS-wrists and back do not appreciate this loss one bit. 
What's the exact command that you ran (or what's the name of it in the default toolbars/menus if it's not a custom button)?
Are you able to recreate what happened? If so could you post a before and after screenshot?
Were the source and destination folders on the same computer/harddrive, or was one a network drive or USB drive, etc.?
I've just done a couple of tests with the Update Existing and Update All buttons and they worked correctly here, for what that's worth.
"Update (copies)...." button. Worked fine until today's disaster.
Yeah I can recreate what happened. But I can't recreate PROPER action.
One was USB --- not previously a problem. Time stamp is being IGNORED.
There are "Update Existing" and "Update All" buttons under File > File Commands but I don't know of an "Update (copies)...." button anywhere so I'm not sure which command you ran.
EDIT: Just noticed that Update Existing and Update All have "Update (copies)..." in their descriptions, but which of the two was it?
Could you hold alt and then click on the button, then tell me what the command it runs is?
If you can reproduce the problem then those "before" and "after" screenshots would be really helpful in understanding exactly what happened and investigating/recreating it on our own machines.
FUNCTION: Copy UPDATEALL
TIP: "Updates (copies) from source to destination all files that have changed (have more recent timestamps) or don't exist at all."
Thanks. Can you show the before and after so we can see what went wrong? I've tried the command a few times without any problems here so it's hard to know what to try without seeing an example.
No I can't show before and after. If I could restore the before, I would not be asking for help.
You said you could recreate the problem so I thought you'd be able to show some screenshots showing what happens. (Not what happened the first time, obviously, but showing what goes wrong with an example set of files.)
"Recreate the problem" means every attempt gets wrong result. Please look back at my first post.
So if every attempt goes wrong could you please take a screenshot before and after an attempt to show us what happens?
Maybe I'm confused. 
"Maybe I'm confused." Seems so.
No need to be rude - Leo is trying to help you after all. Asking for a screenshot is perfectly reasonable given that you are the only one who seems to be having this problem.