yes, I have been refused when I bought this house. Well, not totally refused. I had a doctor at the time who showed me my psych notes that the insurers had seen and annotated. Of course I had attempted suicide and taken street drugs. So all point blankly refused, but one did offer £735 per month for the first 5 years and then £335 for the rest of the term!!!!!!! I was going to go back recently since it has been 6 years since my diagnosis of BP. But now I'm going back to a unit next week very possibly, which I guess won't help. However, I have seen sites/insurers set up especially for BP and insurance http://www.mdf.org.uk/?o=1894
maybe you could check this out?