Microsoft Project Server 2003 Notification Issue

Hi,

I have a Windows Project server 2003 standalone running on w2k3 standard sp1. We have an issue where a user in Microsoft Projects 2003(client) changes the work complete field and no notification is sent out. When changing other columns like duration or adding a new task, an email is sent out to the user and other users involved. The email notification is setup in PWA and no errors are being thrown. Is there a configuration that I might have missed or is this some sort of bug? Any help will be deeply appreciated. Thanks in advance.