Anyone trying to buy stackable ("Arduino-style") headers from eBay, "elec_mall2012" is the only Chinese seller I've come across who actually shipped stackable headers. All the others shipped normal ones.

The other sellers were always very good about refunds, but shipping takes so long that it's still a waste of time. Would recommend buying from elec_mall2012, or just shelling out the extra few euros to buy the headers from a US or EU component dealer.