ARP dataclass may contain programs which is not found in Add Remove Programs on a client
Inventory Solution 8.x
Software scan is traversing into all user profiles.
Some other user has this software listed in add remove programs and found in its registry.
Software name and Username involved can be found in inventory cache file [C:\Program Files\Altiris\Altiris Agent\Agents\SoftwareManagement\data\SoftwareCache_v2.xml]
Working by design