The Bit-x payouts can be a bit cranky. My original payment slot was on a Tuesday. Due to multiple delays that's now slithered across to Sunday morning. They always pay out but it can be a little hit and miss. I think it's often something to do with the blockchain.info API.
Happened to me this week, shifted from Wednesday 6 to Friday 3. It was a bit odd because i was overpaid as if post made between that time frame did count, but only if i remove about 10% of the overall payment. I was shorted 10% the week before again so it could be possible, but its hard to say now or pretty much impossible because of the shift.
Now with the limit removed i'll have to take note of my posts counts and make screen shot to not forget. But it's not too bad because sooner or later, Marco comes through and give you the dosh.
As long as you don't rely on the payout to be always very accurate, its probably the best signature campaign(?).