RACE RESULT 1 M Schumacher (Ferrari) 2 F Alonso (Renault) 3 R Barrichello (Ferrari) 4 J Trulli (Renault) 5 J Button (BAR) 6 D Coulthard (McLaren) 7 K Raikkonen (McLaren) 8 JP Montoya (Williams) Race result in full Pictures from Magny-Cours

"I am very disappointed. I expected after our last pit stop to get out in third position but we had a problem pulling away and that was it," he said.

"We would have been in front of Jarno Trulli and Rubens Barrichello and I think we would have pulled away."

Instead, Button came out between the two men, and lost a place to the Ferrari driver at the Adelaide hairpin.

"We finished fifth which is a bit disappointing and we need to work out why that happened and hopefully resolve the problem as soon as possible."

BAR said the car's anti-stall device had activated erroneously.

"I'm hoping for a good result now at Silverstone [next weekend] but it's difficult to say what's going to happen at the moment.

"The circuit is sort of similar to here - a lot of high speed - so we know the car does work well but we just have to work on our pit stops.

"The actual stops are good it's just pulling away that we are getting problems with."

Button's team-mate Takuma Sato retired with the latest in a series of Honda engine failures.