in reply to
Re^3: Rename unreliable on Windows
in thread Rename unreliable on Windows
Thanks for that one!
It was indeed my backup sw (WD anywhere backup). After disabling it, the test script runs to 10000 loops without errors.
Followup question: why does this happen and is there an easy workaround (apart from disabling the backup sw)? I mean, I don't think I've had problems with deleting or modifying files, only renaming... And I don't think I've had issues outside of perl.