I've had this problem on my '04 C3 senso 1.4 HDi intermittantly from brand new - usually happens in cold weather, when the engine is first started. (and very occasionally when the engine is hot) Car starts OK but as soon as I select reverse and press the accelerator, the engine starts to falter and after a second or so the car stalls violently, and I do mean VIOLENTLY, the whole car really shakes - it feels like the transmission has taken a terrific beating. Very occasionally the faltering engine note is accompanied by a ratcheting sound, as if maybe the gear has not fully selected. This started happening within the 1st month of ownership (Sepember 04) and repeated checks by the dealer have failed to find any fault - after 5 years I stopped reporting the problem, it still happens but I now have almost a sixth sense about it and when it's about to happen, I quickly turn the ignition off, wait a couple of seconds and it always re-starts OK - still catches me out occasionally tho'...still scares the s###t out of me. The most annoying thing about this whole episode is that the dealer didn't appear to believe it was happening ( "......it doesn't show up on the computer mate, so it must be your imagination.........." ) The car doesn't get used very much (still under 20,000 on the clock after nearly 7 years) but I'd dearly love to find a solution to this problem. :) ............... :)