Open the ~ menu, and click on the item in question, should give a ID. If it shows something other then a 00 file, you've found something with a different mod. Unless it's a floor texture, or something.
Wow, I'm stupid.
Okay, a few things then.
0006c21f
0006c220
0006c221
0006c67d
Most of those are floating objects on a couple of office desks in the Red Racer Factory.
008f330
The above is a barn at Chaste Acres Dairy Farm, near the Republic of Dave. It doesn't properly line up with the ground in a number of places, including the walls and the steps inside it.
EDIT: I have come across a quest bug. When talking to Paladin Hoss at Falls Church for the first time, the player is asked to help out with finding Initiate Pek. At the first dialogue choice, if the player selects the "F uck off" option, negative Karma is granted. This is repeatable, for infinite bad Karma.
Several terrain errors around the Falls Church and Marigold Station areas:
000a4e6f
00031240
0005f10a
000a4e89
00031236 (under train)
0009d726
0002299c
00082d41
The above are all piles of rubble that do not come into contact with the floor entirely.
0009d6f1
0006434f
0003123a
The above three are pipes that clip into the floor noticeably - these may not be correctable as I believe the pipes are attached to the rubble meshes.
00022af5
00022b42
The above two are noticeable holes in the rubble piled up inside this building; one allows you to see off into the void.
00020d4c
00082c77
The above two are flickering ground/sidewalk tiles.
It's amazing what you can find while just playing for an hour or two.