Without saying they shave or not etc...I can tell you with CCBILL it works like this
Example my paysite is paysite.com :D
You visit
www.paysite.com think, nice site...you join webmaster program.. You clean cookies etc, and send traffic to
www.paysite.com/?yourID
Now you join etc, and guess who gets credit...The one who FIRST sends that IP(it stores the IP for 24 hours)
Not saying it happend here, but it COULD BE one of the reasons...
Since I don't use Ibill, I can't tell you IF this is the case, it just COULD...
Andre