Strange compatibility problem between ver 2003 and ver 2007

I don't know if this is a one-off through some corruption in the workbook, but anyway here goes:

I have a workbook created in Excel 2003.

The code in one macro duplicates a hidden worksheet, then makes the new (active) worksheet visible, and initialises the values in some of the cells. It works fine when running under Excel 2003.

Then I tried to use the same workbook in Excel 2007 (in compatibility mode) and it would not make the new worksheet visible, nor would it initialise the values in the new (hidden) worksheet.

I got around it by changing the code so that it made the hidden source worksheet visible prior to duplicating it, then re-hiding the source worksheet. Well, I haven't had a chance to test that this works in the 2003 machine at work, but it now runs OK under 2007.

So I am not looking for an "answer", as I seem to have one. But it would be nice to know that I am not alone.