I encountered a small bug earlier and didn't see it posted. I was trying to buy a bottle of Pear Wine at 57 Zorkmids from a vending machine. I have exactly 57 Zorkmids and it wouldn't let me buy the wine. A bottle of Hard Cider was in there at the same price and same thing happened. Soon as I picked up a few more Zorkmids I was able to buy the wine. My guess is you can't buy something that will put you to 0 Zorkmids (at least from a vending machine) Sorry, have not been able to test more than this time so far, at work right now (shhh :-P ) So might be some odd isolated incident. Hopefully someone else can confirm this or not.