triumph dave

I've a 2005 2.0 diesel S.E. My problem is with the engine speed not always dropping to tickover,but only dropping to approx 1000rpm.It doesn't seem to do it when car is stationary,but when engine braking or slowing down and changing down a gear.All of a sudden she seems to lurch forward rather than slowing down.Now I'm aware that it can happen,I'm prepared for it,but obviously somethings not right. Any help appreciated. thanks

top left on the instrument panel.2 switches side by side(left and right seat)mines a 2.0 SE diesel