Easy there chaps, dont scare Mr G. I had exactlty the same problem, jumping out of second on engine breaking, and occasionally in third under heavy acceleration. Turns out it was one of the cir-clips split and broke off the lay-shaft (apparently common on the 16v engine). I had a local garage sort it out, they stripped the gearbox (manageing not to fully take it out), re-install the new part and had it all fixed in one day. The shalf (think the 2nd gear cog) was rubbing slightly on the casing, so had some burring in the box oil. Had to flush it again a few weeks later just to ensure non left. All sorted for £110.. bargin. Worth checking before you start buying complete new boxes, etc... 5000 miles on, its all still a going like a dream..