@apro: go to what.cd/invite.php and if you see an email box then you still have your invites (otherwise you'll see a message Your invites have been disabled). Right there you can also check your invite tree.
He has a positive feedback from a user who was trying to buy a what.cd invite a day or two ago. Then today he is having issues with his invites. I'm no detective but it's pretty clear what happened.
Maybe you're not a detective but you're definitely detective material