Collision events in scripts take a long time to fire. This is noticeable in the popgun, as the bullet bounces off a considerable distance before stopping. Here is a demo script: default { collision_start(integer total_number) { llSetStatus(STATUS_PHYSICS,FALSE); llSay(0, "Impact"); } } Put this in a cube, and drop the cube on another cube or platform, and see how long it takes to activate. The amount of time it takes is random, sometimes it's quick to work but sometimes it takes up to 10 seconds.