Even Dan Carter admits the troublesome World Cup ball has given him headaches.



Rarely one to create controversy with outlandish comments, the All Blacks first five-eighth admits the controversial Gilbert "Virtuo'' nut is proving a difficult ball to master.



And the statistics speak for themselves: Carter has seen his success rate during the World Cup tumble.



During the Tri-Nations the sniper nailed 75 per cent of his shots with a different brand but has only nailed 67 per cent of his attempts during the global tournament.



The ball has provided plenty of debate throughout pool play with players and commentators all having their opinions about why it is proving so difficult to send through the sticks.



There have been a raft of excuses, ranging from the weather conditions and stadiums, but when a player of Carter's status admits to having some frustrations in accommodating the Gilbert product it is obvious there are some issues.



"Yeah, it can be (frustrating) at times, but obviously when you play with a certain ball you get used to it,'' Carter said.



"And to have a new one just for such an important tournament it can be frustrating early on. But that is just a matter of getting out and working hard on the practice pitch.''



Carter said he had a couple of weeks before the tournament to train with the new ball, having grabbed a few off baggage man Errol Collins when the All Blacks travelled without him to Port Elizabeth to face the Springboks last month.



Unlike some other balls, those issued for the World Cup are not as forgiving; if a kicker doesn't execute the perfect hit with their boot, they can pay the price.



"It doesn't have as much give,'' Carter noted. "So obviously if you don't quite strike it right then it doesn't fly as straight as you would like it to at times.



"But it is the same for every kicker and is just a matter of continuing to work on the practice pitch to make sure you're fine-tuning your routine and rhythm to make sure it is well on tack. Because if you strike it well - then it goes straight.''



The ball being used in New Zealand is made by the company that has produced them for every tournament since 1995.



After England's Jonny Wilkinson and Martin Rodriguez missed 10 attempts between them in their opening-round clash at the enclosed Otago Stadium, some questions were directed at the ball's manufacturer who denied their product was at fault and said each one had been checked by their "ball engineer''.