i noticed today (in 3.3.5) that enchanting materials now have a 1 silver deposit on the AH. before today, enchanting materials had a 0 deposit. I used that fact to maintain large numbers of unpopular enchanting materials on the AH without the risk of losing money. some of the low level enchanting materials sell for 30 copper and less. with a 1s deposit, selling low level enchanting materials will no longer be profitable (at least in small stacks).
i hadn't payed much attention before today, so it is is possible that this change happened earlier without me noticing.