Forgot to post any results! Well, it started playing up again after a few days, so took it in to my local independent land rover garage, Sayers in Ashford, Middx. They gave it the once over and found no messages on diagnostics, 3 glow plugs not working as they should but, as discussed, this probably wouldn't be the problem. The pump output was apparently not perfect but above what it requires. They then looked at the injectors and found one was returning a lot more fuel than it should. They recomended changing that, which i gave the go ahead for. I got it back, put some injection cleaner in, filled her up and haven't had a problem since, touch wood.