Thanks nicholas for your comments (and peters) but i found the
solution. Staring me in the face for a week was a spelling error. And
it's here above me in the original post. Exectute rather than execute.
It's weird how the brain can just bypass spelling errors.

What's weirder is that the error message didn't look like a normal
spelling error. Something like 'property not known' at line xx would be
something to expect .. but since it looked like it was an attempted
execution that's where my thoughts lay. And since i hadn't come across
miracleous appearances of slash characters in sql strings before i
presumed that it was my lack of knowledge on mysql or ado maybe.

Andy