Unfirm Jobs and Time Phase

Hi, all.
Our Purchasing Manager wants to know if there is any way to stop unfirm
jobs from showing up on a Time Phase Rpt. I've looked around, but can't
find anything (check box, whatever) to prevent it. Am I missing something
simple, or is this a "feature" of Vantage?

Thanx,
Alan Williams
Vantage Admin
Stone County Ironworks