Excel Pasting Values and not Formula
 

I've recently upgraded (poor choice of words) from 2003 to 2007.

In some of my workbooks (lots of code in them) I can no longer copy and
paste basic formula between sheets in the same workbook. Within a sheet
there is no problem. These files have been saved as Excel Macro-Enabled
Workbooks.

With new workbooks there is no problem. I was wondering if anyone knew
what was going on as its driving me up the wall.