Limit to Conditional Formatting
 

I have data that is in three columns by ~3000 rows.

I want to apply conditional formatting using icon sets such that for each
row it looks at the three values and displays the appropriate icon.

The problem: When I highlight all cells and apply conditional formatting -
it doesn't take. The icons don't appear. However... If I select a smaller
chunk, say 100 rows of data, it does work.

Does anyone know if there's a limit to the number of cells conditional
formatting can be applied to at once (or some other reason for this behavior)?

Thanks.

--
Jeff