OK, I hope I explain this where you understand if not please let me know.
This bug is occuring on the test server.
this bug can be recreated quite easilly.
1. chop down a tree,
2. chop into large logs or small logs.
3. Exit game log into another character at the same location.
The tree will be back in choped down position . So you can then chop it back into large or small logs. The prior large or small logs remain.
While this is handy for experimenting on stacking logs, I think all can see issue of this duping bug. :P
anymore information needed please let me know more happy try stuff =).