Abu Dhabi\'s comeback was put on hold on Thursday when the team became the latest victim of the structural problems that have blighted the fifth leg of the Volvo Ocean Race. The team skippered by British Olympic silver medallist Ian Walker announced that they were slowing down the boat to give themselves time to study delamination of the hull, a potentially dangerous situation. Four of the six teams have now been affected by serious problems, meaning only French team Groupama and American rivals Puma are racing at full pace as they bid to be first into the Brazilian port of Itajai. At 1800 GMT, Groupama had a 55 nautical mile advantage over Puma with less than 24 hours before they reach Cape Horn on the way round to Brazil. \"We can really feel the pressure from Puma,\" said Groupama\'s helmsman Thomas Coville. \"They\'re trying to stay with us but we need to show we are faster. We are involved in a real game of poker for first and second.\" Telefonica are clinging on to third place, which they will need to hold all the way to the finish to be certain of retaining the overall lead. The big question is whether Abu Dhabi will be able to make repairs and get back to full pace in time to challenge Telefonica for that third podium place. Telefonica have already stated that they plan to make a pit stop in Argentina, meaning the opportunity is there for the Emirati team if they can recover. Camper, in fourth place in the leg and third overall, are on their way to a pit stop involving a much longer detour to Chile. That means they are almost certain to lose further ground on Telefonica come the end of the leg. Overall standings after four of nine offshore legs: 1. Telefonica (Spain) 122 pts; 2. Groupama 107; 3. Camper/ETNZ (Spain/New Zealand) 104; 4. Puma (United States) 83; 5. Abu Dhabi (United Arab Emirates) 55; 6. Sanya (China) 25.