I've tried breeding ferroseed and charmander with ditto and every time I hatch the offspring I get a MALE. This is getting irritating and I started to wonder whether the breeding mechanics with ditto changed. Did they?
Breeding Mechanics did change, but the offspring's gender depends on the Pokemon itself. Ferroseed/ Ferrothorn have a 50% chance to be either Male or Female, but Charmander/ Charmeleon/ Charizard has a 87.5% of being Male and a 12.5% to be Female. Here are all the changes in breeding.
No, the breeding mechanics haven't changed with Ditto.
If you are breeding for Charmander, it has a 87.5% Male/12.5% Female gender ratio, so you will get more Males than Females.