FBI received my prints via FedEx early Feb 2011 and they charged my card on the 8th. I had sent them a FedEx waybill to return as I live in the British Virgin Islands and post is ridiculously slow. I started to get a suspicion around early March that maybe they had sent it via snail mail against my requests. I sent them an alternate address on the afternoon of 9 March.... and what do you know, they alredy sent it USPS to my BVI PO box that very morning! I freaked out, knowing it was the last document I needed to complete my packet and could take anywhere from 2 weeks to 2 months to arrive but slowly calmed down and resolved to just send it anyway with a letter and proof it was on its way.
On 24 March (my birthday!) I was heading to FedEx to drop off my application and decided to stop at my PO box.... low and behold, there was the envelope. Best birthday present this year! I was shocked by how efficient the whole thing was......