Hi Claridge. Yes you are right and I never knew that. It seems no matter what format I save some HTML code as from textedit, I get the same problem. Use that same file and open then re-save from DW or Coda, and job done, so it seems ending a textedit file ".html" is not enough for a browser.
Obviously more to it than previously met my eye - thanks, I'll beware of that in the future.