Well I have eventually been so see my NHS physio (a runner from OtleyAC) and it transpires that I don't have ITB at all, but he couldn't put his finger on exactly what it was. Most likely explanation is a 'pinch' of the 'mesh' that holds all the knee gubbins in place. Unfortunatley my short runs to maintain a little fitness seem to have exacerbated the problem. I have been advised to take another 4 weeks off doing nothing! ahhhhhhh.

Oh well. at least he said that it was probably nothing serious and hopefully next time I see him the problem will have healed.