Weights mirroring properly on back legs but not front legs

So i have a mesh that has the mirror attribute. I put in bones and did the auto bind, which worked fairly well, with one exception:

On the back legs, the weights are mirroring properly, and each side controls the corresponding leg. However the front legs are acting funny. The left leg has all the weights mirrored across both sides, and the right leg has no weights. I’m sure its something simple, but any ideas?


Without the .blend, I can only guess the front legs (or their vertex groups) have some error in their naming.