Assigning "Normal" Importance to incoming email

Hi,

I have the Rules Wizard set up to assign an importance level to
incoming emails which I then group by. The problem is that many receive
a level of "None" even though the Wizard is supposed to give it a
"Normal" level. The "High" and "Low" assignments work fine but for some
reason "Normal" only works sporadically resulting in a few "Normal"
assignments and a lot with "None."

Has anyone found this quirk in their settings?

Thanks, Steve