MakeClothes symmetry weirdness

[learning]

I'm still trying to adapt boot models from blenderswap to MH, and I encountered a rather weird bug. I did the following: loaded the human at exactly 0,0 of the xy plane, imported the boots mesh, put it at 0,0,0 as well, then went into edit mode, removed the left boot, fitted the right boot to the human and then applied the mirror modifier to get the right boot. In blender it fell perfectly in place, but after exporting with MakeClothes it turned out that the right boot is significantly to the right from how it should be. Why does this happen? Is this some sort of MakeClothes bug or something else?

[duststorm]

after exporting with MakeClothes it turned out that the right boot is significantly to the right from how it should be. Why does this happen?

Because the vertex group assignments are non-symmetric. Check and fix them, then run MakeClothes again.