Excel 2010 conditional format slow

[Tom C]

I recently upgraded my Excel version from 2003 to 2010 and am having a problem with a simple conditional format that worked in the previous version and sort of works in the current version

The worksheet does the following conditional format:
-if the current cell matches any cell within a specified range then change the current cell fill color to blue

In the previous Excel version, once a matching entry was entered into the range, the current cell "immediately" changed fill color.

With Excel 2010, if I input a matching entry in the range, there is no change in the current cell's fill color unless I scroll away to the point that i cannot see it the current cell on my monitor. For example, if I page down a full screen and then page up, the current cell is then blue; If i ALT+TAB to a browser and then back to Excel there is no change in the current cell fill color.

Any help is appreciated.

-Tom

[martindwilson]

hmm i notice something similar in 2007, sometimes the cell only partially filled or not at all. very strange