Many people on the internet seem to have stumbled across this bug, so much so that the ubuntu docs on
https://help.ubuntu.com/community/FilePermissionsACLs even report that ACL's are rendered ineffective due to this bug in coreutils (cp/mv). I have run across this bug as well, which is very annoying in a shared environment with multiple users in different groups using the same resources. Is there any chance this bug will ever be fixed or is maintenance on ACL's or coreutils not happening?
Dolf.