Hi All, Thanks for all the useful comments. Buster gave me quite stable refinement and nice maps, so I've been working with that so far. I'll work through the other suggestions however, and see what gives the best results.
Cheers, Rhys -- Dr Rhys Grinter Sir Henry Wellcome Fellow Monash University +61 (0)3 9902 9213 +61 (0)403 896 767
