Unwanted combining of Conditional Formats
 

I have multiple cells with the same Conditional Formating (each formating is
set individually). However, after saving and coming back to the spreadsheet,
I see that Excel 2007 has combined those Conditional Formats into a single
one (such that the "Applies To" box contains a range of cells instead of just
the single cell reference.

How do I prevent this from occuring??