Maybe this is something I am not doing right.    I am not a building or texturing guru, but when I copy a prim and drag it next to its copy the two do not align, in fact they are stair-stepped off in the same direction by the same amount.   Could this be part of the same prim drift that is impacting sculpties?  

It happened to me today with some non-sculpt prims.  Moving then moving back put them back in the correct alignment.