Nuke-Xtreme 60044312 in Dry Rock Gulch in the spectator stands, up the ladder and on the table needs Havok/physics removed as it falls through the roof 95% of the time especially if you grenade the bugs in the area. WiKi also states this, as that is how I found where to where it went, although that was my suspicion. I needed to TCL through the wall to get it and it lays in the floorboards. This has ben the same on the last 5 playthroughs.