One must also remember that Chopin had a much different piano than us. Also, the pedal markings that are there are not to be taken to be exact, for a number of reasons. For example, there may be editorial decisions. Also, these may be pedal markings that are clarifications, for a pianist may want to instinctively want to pedal one way, but the composer specifically specified something else. The moral of the story here is that one must make their own decisions based on what they think is musically most appropriate. So, basically, I'm just expanding on what tea cup wrote (haha, I didn't read it until a bit into this post).