Hello,
First are you doing the inventory on the deployment server with "Get Inventory" or on the Notifation Server with "Inventory Solution"?
If it is on the deployment server if you right click on computer and choose "Advanced" then on the sub-menu "Get Inventory" wait 3-5 minutes and check the "Properties" by right clicking the same computer and choose "Application" is it updated properly?
If it is on the Notification Server you need to wait a cycle of the Altiris Agent and also the process of the Software Inventory from the Task Tab which could run daily, weekly depending on its schedule.
Let us which one you are using and I could detailed more..
Thank you,
Dominique