I had something similar but it has something to do with their weird authentication process. Was yours a credit card or a debit card or some other kind of card? I noticed the same thing on a debit card I used with them, but in actuality it was just a secondary hold. At least it was in my case. I talked to them about it. It seems like they do screw it up from time to time, so I agree watch them.
As for verification, I have multiple accounts with them and in all cases I called them on the phone and had it verified within a minute or two.