Thanks folks. I got some ointment today and I am going to try to take Greg's advice about laying off the practice for a while. Goes against my work ethic a bit, but I guess there's a reason for it! I am gigging at the weekend, so a complete rest is out of the question. It could well be the new piece I have been attempting. I changed my habits a bit when I took lessons some twenty years ago. I do try to get my left hand in a better position over the guitar, but I guess there is always room for improvement. Thanks again for your help.