Just thought I'd better check out what the actual higher rate of income tax was for working out dividends:
http://www.direct.gov.uk/en/Nl1/News...2008/DG_072925
I actually thought the 40% rate was around £40,000-£43,000 - so was pretty surprised to see it at £36,000.
I guess I've been making a simple mistake of thinking 40%=£40 at some point and never got around to correcting myself.
Quite lucky really, as I thought I was under paying myself with dividends, but it looks as though I had myself a lucky escape - I could have been paying more and fallen foul of paying a lot of tax by accident!