When an agent sits on an object containing a sit target in Havok1, the relative position of the agent to the prim is offset by a small amount based on avatar geometry. In Havok4 this offset appears to be absent, which will change the behavior of the sit target for ALL objects containing sit targets. I tested this in Havok4 beta, and confirmed in a havok1 sim within the beta grid that the offset still exists there. Reproduction: 1. Go to a Havok4 sim. 2. Rez a box. 3. Create and run the attached script "Sit Target Offset Test.lsl" in the box: 4. Sit on the object, and observe that the result is <0, 0, 0> 5. Take the box to a havok1 sim and repeat, the result will contain a small offset in the Z coord which varies based on avatar geometry. I am calling this a bug because it will somewhat break existing content. If the change is deliberate, then objects with existing sit targets will need to be adjusted by their owners or creators where the change (~0,.04,m) is considered significant.