So, I went to sell me leftover pistons at AlexChance 4005. And I got this nice little error where even though I have 7 pistons, it still says Not enough items to sell. The same error occured at 4445, 3004, 3003, and a variety of other shops.
Yeah this problem has already been reported several times, I think aikar may be working on fixing it.
http://track.empire.us/issue/EMC-48 Was supposed to be fixed, I updated my shop signs at 4005 although the other res's probably wouldn't have been.