RDG, I have some more answers for you.
Number 1, I was told that there was never any con "returned" by the smelter.
As far as problems,obviously there were more than a few, however one of the biggest was that they did not spend the money that they should have on getting the metallurgy done before starting production. Apparently there was a great deal of pressure to get into production, and they just started feeding ore through resulting in lower percentages of recovery than they expected.