We've never seen this. Please provide the steps to reproduce it if possible.
Matt:
I do not know how to reproduce this, BUT
it has been reported on a number of occaisions by myself and others that erroneous duplicates are shown within MC.
I do still come across this but have become so used to this being this way and over time have become accustomed to "filtering it out mentally' . . .
in other words, I ignore it as it has been pretty much ongoing for some time.
If I go to my "Auto Smartlist - Task -- Possible Duplicates" I can find several entries showing this condition (all fields/tags and filename/folder are identical for each of the pairs of two files shown as duplicates, yet if I open the folder in Windows there is ONLY 1 file in existence . . . yet MC's library database shows two identical entries.)
I have also seen triplicates . . . . and even using 'Rename files from properties' does not remove the duplicate entry even though we know there CANNOT be more than one file with the same name.
I am fairly certain others can confirm this behavior as I have seen it mentioned in the past and do not remember it being resolved.