I think that trees goes nuts!
My paesant still keep harvesting trees every chop a new one.
Seems like the trees have no more than 2 or 3 unit of wood inside.
I posted this both on paesant and economy bug posts, because i dunno if the guilty are trees or paesants.
But things went worse since trees are not selectable and don't show stored wood anymore (most of them, not all, some trees still display it if clicked).