Altiris Software Inventory - Does it use the registry?

I have a Reflections program that has been uninstalled on about 2000 machines. On maybe 100 of them it still shows installed even though there is no mention of it in the registry under HKLM\Microsoft\Windows\Current Version\Uninstall.

Does Altiris look at specific registry keys to see if something is installed? Just wondering if maybe there's a key I can delete so that it will stop reporting back that it's still on there.