Sorry, i really do love pd, and feel like lately all i am doing is
complaining about fiddly annoyances, but this one has gotten me repeatedly,
and i felt it might be easy to fix (?):
If you copy an object (ie: ctrl+C), or select an area and copy all objects
inside that area, and then paste directly again (ie: ctrl+V), the newly
created objects are actually placed UNDER the original object.
So, when you try to move the newly created object, you end up moving your
original.
This gets particularly frustrating if you copy/paste a big bunch of objects
at once, and then do something else before realising, and can't access the
undo function any more.