Hey Ash. Can't reproduce it from scratch, and while I was attempting to strip down the project to just the bug, I found that deleting a certain layout (TutorialDefunct) fixed the problem. Deleting individual objects from that layout didn't seem to fix it, nor did the problem occur with the sprite (Laser) in that layout. Very confusing.
The problem should be evident just by running the "OrwellMansion" layout in the capx I PM'd you, without requiring you to edit it for a period of time.