Steve, this is what I found re "out of bounds script errors"
1) The script looks at the path and reads the orientation of path at the points where it is going to copy the "copytarget". If you adjust the individual points on the path in different views, you can inadvertently change the orientation of the path in totally unpredictable ways. For treads (and similar things), I used the Build->Primitives->N-gon to make a circle and then stretch it out.
2) Your "target" object's pivot was at the origin of the screen rather than in the center of your object. Your object's orientation is measured from this pivot. The only way to move that is using the Object/Axis button and manually moving it to the center of the object.
3) Your "target" object's origin was also at the screen origin, rather than your point zero.