Canderis

Ah, interesting

Mostly, I had this sort of mess with copied objects, like crates and things. So yeah cloned

I believe it helps, when you cloned the objects, to Convert them to Mesh, make sure the Pivotpoint is centered. Then resestxform.

Else I suggest this, not really sure if that really helps: Pick your object, go to the pivotpoint. Center to object and then, with Pivotpoint still active, Resetxform.

If your object was rotated and all, that should put the pivotpoint straight again, but the mesh itself will still be turned. IIRC, this helped me with object facing the wrong way in the game.