I've noticed a few posts about this problem albeit a few years back and i'm not sure if there is any surefire solution.
The problem is the engine management/transmission warning light (the one with the spanner appearing through the car roof). In a higher gear, above approx 3000 revs, this warning light comes on and the car switches to 'safe mode' or limp home mode as it appears to be called on this thread. If i turn the engine off and then restart the light disappears.
Is there any new insight into the cause of this fault or an quick remedy as it appears to be something that is realatively common.