...
bitmixer.io is indeed a legitimate service, I have used them many times.
My best guess is that transactions of very low amounts (and especially very low fees) are the ones with looooong confirmation times.
Two examples:
1) A few days ago bitmixer sent a small payment to ME, but it took some 40 + hours to confirm (as they sent the payment with a close to $0.00 miner's fee). I did get it confirmed, but it took a long time.
2) As a test during perhaps the worst of the "stress test" spamming attack (July 6), I sent myself a small transaction of about BTC0.005, but with a large fee: BTC0.0006 ($0.16). The transaction was confirmed on the next block. Reconfirmed on the one after that.
Notice the pattern? Be a tiny bit generous, and you get your payments confirmed. Be really stingy, and the miners will not bother confirming you when THEY are under attack as well, and not getting any payment.......
I think this post is worth paying attention to. I think it is really important to that people start realize that there is connection between the chance of your tx to be added to a found block and the size of the tx fee. It is really up to the miners if they want to add your tx to the block or not, but a high fee will really increase your chance. I have noticed that when cyber-bank-robbers steal bitcoins from the bticoins exhance then do they use 1 BTC in tx fee, in these case then was the tx included in very next block. Not saying you should pay that much, but if you have a tx where the addresss is valid for a time limited time, then pay a good extra fee, in the case in OP, then would I have paid 0.005.
