Okay, before you all get mad at me and get off topic about how using a Shark is wrong - yes, I did shark a Ditto, but only for breeding purposes.

Now, seeing as how that's out of the way, the problem is the Ditto I sharked won't breed with any of my Pokémon. I'm trying to get a female Treecko but it just isn't working. I like to breed all my Pokémon naturally so I can raise them as I see fit. How do I get a Ditto that will breed? Is there a special way in RS? In GSC I had no problems with this...