Bukkit

I play on D'hara server and the fancy shops doesn't work with double chests.   I can set up a shop, test it out, and it works fine, but when I return a couple days later the items are gone and there is no payment.   I'm not sure if the items are spontaneously despawning, or whether someone is exploiting a bug, but I suspect the former rather than the latter, as one of the chests had only eggs in it, and who would want 600 eggs?
Single chests work fine.

Correction, single chests also have issues also with spontaneous loss of items inside. Doesn't seem to be any identifiable trait on what type of items are lost. Items are lost from regular single chests and trapped single chests also. When I test things out it all works fine and looks fine, but when I return the next day, stuff is missing and there is no payment.