Well would you Adam and Eve it!

Three hours of frustration at the compile error and it turns out to be 'environmental'!

I ran your code in the current workbook - same issue.
I ran it in a new workbook, worked fine.
I then reopened the original workbook and then the code worked without the compile error.

In a boolean environment, how can true or false become neither?

Thanks alot for this - I'd have been faffing about in the same workbook all afternoon without your help - it triggered me to reopen it and now all is well again in the universe of ones and zeros.