Not sure if it was reported, or if it's not even a bug, though I highly doubt it.
I chose to start as a noble, hired a guy to manage finance (whatever they're called, sorry I can't remember). Anyway, when I choose to upgrade anything it would give me a time and cost like normal (IE The mill...blah blah... 5460....blah blah..... 36 days or however much it was exactly). So I agreed, a mill seemed a good investment for me anyway. Now, I clicked on manage village and noticed it said the mill would be finished in only ONE day. I then checked my treasury and I still had the 5k in it. So I thought that the money would be withdrawn gradually or when it was done. WRONG. The next day, my superb peasants finished the mill and I was charged nothing. The village was rich, but I doubt that has anything to do with it. Correct me if I'm wrong
While I love the fact that I am now getting nearly free, nearly instant upgrades (I still need x amount to START the upgrades, it's just never charged) I don't think it's suppose to be this way.