In the original Lost season, the producers had gone the cheap way and cast a rather poor Frenchwoman knock-off who could barely read her lines phonetically.
In the last season, the bunch of French castaways is actually played by real French-speaking actors. Except this time one of them has a very thick Quebecois accent (for a vague English equivalent, try to imagine something like a Californian character played with a strong accent from Ontario).