[Closed] problem with temporary meshes

I’m trying to do the following

                                          make a copy of a scene node.
                     apply a rotation to that copy
                     save the resulting mesh to a variable
                     delete the copy
                     then apply further operations to the mesh contained in the variable.                     

                                          When I try to do this, maxscript is giving me a “Runtime error: Attempt to access deleted TriMesh”

I can’t understand why, when the operations that flag that error have nothing to do with the mesh that was created then deleted.

                                          Here’s a bit of the code :

-- Takes a copy of the child object from the array of children selected in the plugin UI
local tempnode=copy thechildren[i].node 

-- orientchild is a function that rotates the object without affecting the pivot.
 local reoriented = orientChild tempnode.mesh (inverse thechild[i].objTM) 

-- This transfers the mesh to a variable that stores the mesh data
 thechild[i].tmesh = reoriented 

-- we delete the copy of the original node
 delete tempnode 

 -- This line flags up the runtime error !!! argh...
 thechild[i].numfaces = getnumfaces thechild[i].tmesh 
 

                    perhaps there’s an easier way to rotate the mesh from a scene node without actually effecting the node itself or needing to make a copy. 

                                          Any suggestions?