I'm celebration of the things being fixed in the newest patch I wanted to see how much money i could amass, but I appear to have found an issue with Imps.
I built a few large treasuries for the hell of it, but found that my imps only felt like filling up one of them. They kept digging at the gems until the gold piled up so much that they couldn't dig anymore, but they aren't carrying it it to the other treasuries. BUT, if I connect the middle treasury either of the ones beside it, they will fill both up, even the one that isn't connected.
Link to the save. It's the one called "holycrapgold"
http://www.mediafire.com/?25pvg2sbx85515d
Also, I don't have a save of this one, but I also noticed that they would sometimes not claim a tile, usually the unclaimed tile was in a corner, but the would leave it unclaimed until I manually dropped an imp on it.