Marlboro Ducati's Nicky Hayden is concerned aboout instability problems with his version of the Desmosedici GP9 and reckons he expected more from himself at the Sepang test session.

The 2006 MotoGP World Champion is struggling to get predictable drive out of corners but says that he is happy with the performance of the new Bridgestone tyres after he knocked over half a second off his best lap time in the last session.

“We started out on the right foot again today and I managed to knock six tenths of a second off my best lap from yesterday. Then in the early part of the afternoon I had a little crash in turn two, where to be honest they’ve done a bad job of resurfacing the track and it has caught a few riders out this week," said Hayden.

"Luckily I wasn’t hurt. Obviously I’m not happy with my lap times, I was expecting more from myself, but I have to stay positive. I’ve improved my lap times every day and we have gathered a lot of data to work from in the next test. The fact Casey is already so fast means that the bike has the potential – it can only be a good thing that he is going so quick.

"The team is working hard and they are just as determined as I am to get the results, so that’s a good thing. I wasn’t too bad in the first two sectors but I was losing too much in T3 and T4, where the problem I’m having with the bike being unstable and unpredictable on the exit was the worst.

"The Bridgestones are really consistent and I was able to do my first long run on the Ducati without any tyre life problems.”