Do you change the schedule every day? From what I see it should run only at 2am on 10/15. Again, allowing users to run is a bit misleading, because it's possible for them to 'see' this task, and execute manually. Someone could really execute it as many times as they wanted, it would just return a 0 (success) once it determines SP2 is already there. Actually it looks like you are using a wrapper around the install, so this would be affected by your coding.
Try to track down some systems and post their Altiris log files here in .zip format, if you want some help analysing them. I don't see it as an error, per se, but I can see you concern.