WOW! Thanks for the quick reply, Purr4Me. That linked post was so insightful. I'll offer a bit more of background on my bugs. As I've said, It is only in the Zeta DLC. I actually have nothing on the static (i.e. meshes, textures, nor collisions) I don't think that it's a Fallout3 main module being corrupted as I've played through the Pitt DLC and Point Lookout DLCs (all with mods relative to them) and never experienced such. I fall through the floor and end up respawning at the map's entry point. NPCs also fall through too but ends up respawning on top of where they started prior to falling (they keep walking and falling which is pretty funny). As for the error message earlier from an earlier suggest fix, It was something about an "ARMO" error which I have no idea of. I should also add that I do have tons of mods related to the Mothership Zeta Crew mod (pretty much all of it's extended quests packs, TSC Air Support, Extra clothing, Expansion Packs, etc.) unlike the other DLCs which had pretty minor mods to them. But, as your linked forum said, these mods are pretty big and supervised to be faulted. I've also lowered down my video settings to it's lowest point as suggested earlier and still have these issues. I guess I have to try that suggestion of setting my video graphics card to not use grids. How do you do that? Thank you so much. :)