Help with my pokemon platinum?

ok so i have got a lv 100 male charizard and i want to breed it, but when i put it in the day care with a ditto, the old man says they dont get along, so now I can't make an egg, so then i tried with a female shieldon just cause i didnt know what to do, and they made an egg but when it hatched it was a shieldon so can anyone please tell me how i can breed my charizard?