One of my Fishing In Skyrim users has a problem: for him, my fishing nets float. They are supposed to sink.

My nets are based off of a NIF animal hide that sinks when I try it, and I even copied it into my own separate nif file just in case Beth screwed with the physics. It SHOULD sink, but for this one guy, it doesn't. Any ideas? collision layer ? havok weight?

Very confused: I always thought this was a Havok thing burned into the model.