Warren Gatland has stoked the fire ahead of Wales' meeting with Ireland by revealing his concern over how the scrum was refereed last weekend.
Gatland said that following their opener against Italy, he had sent a report to referees' chief Joel Jutge querying the officiating of the set-piece.
He was unhappy with Irish match official John Lacey's decision to penalise loosehead Paul James and publicised this ahead of Round 2.
"We were disappointed with a couple of early penalties against us and we have had a look at it," head coach Gatland explained to BBC Sport.
"We have sent it [a report] off to Joel Jutge just to get some clarification because it stopped a bit of momentum for us in the first half.
"Paul James was penalised a couple of times and I have gone through and looked at the tape [and] thought he was pretty unlucky.
"We had a couple of line-out penalties against us for guys coming in at the side and we felt they were legitimate as well.
"So we just want a bit of clarification."
Gatland, who has replaced James with Gethin Jenkins in this week's starting XV for their clash in Dublin, added: "We had a couple of scrums where we haven't been brilliant, but again we have worked on that and hopefully it will be good for this weekend."