OK to resurrent an oldish thread.....
I contacted a dealer (thank you Palmers) and they suggested looking at the fuel I'm using. now I've always been a little cynical when it comes to paying for "better" fuel, but as they replied to me I had just happened to fill up somewhere different to usual.
I usually use ASDA where I work to fill up, and since doing this the car has got worse and worse. For various reasons I used Sainsburys just before Xmas, and since then the car has been back to how it was. Once the fuel had chance to work through the system, the car started much easier and ran much better, much smoother at idle etc. I also have since tried some REDEX diesel fuel injector cleaner. Used the car today for the first time for 5 days, and started on the button, no lumpy starting.
So it seems that the issue can be almost resolved by using a diffeent (or better) fuel.
I'd be interested in hearing others experiences and/or views on this. The car was struggling to start, and at times I needed 2 attempts to get it going, now it consistently starts first time. Lets hope I haven't jinxed it by saying that!