Sorry if I was mistaken that Ditto copys Ivs, but I read it here:
Transforms into the target, copying its stats (except HP), moves (at 5 PP each), type, weight, and ability. The stats are copied exactly, without regard to EVs, IVs, and level. IVs of the target are copied for purposes of Hidden Power, as well.
So if it changed in the 5th Gen, works differently with the ability or on the PO simulator then I apologize.