Posted: 04 March 2012
Overall: Pat, what you have is Escallonia leaf spot. It's a relatively new fungal disease, having only been spotted a few years ago but has spread fast. The RHS website has details on how to treat it (search escallonia leaf spot there) but I guess that more will be found out once they've properly identified the strain etc.
Shame as it's a lovely plant otherwise, but the disease is making it look unsightly and probably weakening it.