@cbae Of course my code doesn't actually look like this but we have complex workbooks with many protected sheets. There is a time when the code unprotects the workbook and then all of the worksheets, manipulates them and then reprotects them. There is a huge performance issue between Excel 2010 and Excel 2013 which is all down to the protection issue.
@ZippyV "Doesn't make sense" Perhaps not in the isolated example, that was just to illustrate the performance issue. I thought I'd keep the post simple so people could understand it
I agree with @evildictator but they've really messed up on this one. I have found other people moaning about this but no resolution as yet.
Anyway, I have had a direct response from Microsoft to say they are aware of this issue and are currently researching the problem.