So I hear this Etude the other day, and I notice I play the bass differently in measure 40 for the last four notes on the left hand :
While the right hand plays B---C-D,
I play A D F A (leading to octave G), as in http://imslp.info/files/imglnks/usimg/9 ... P10_12.PDF (bottom right of page 2)
and I heard A C D A (leading to octave G), as in http://imslp.info/files/imglnks/usimg/7 ... 600dpi.pdf (bottom right of page 37).
Which is the commonly accepted one ? Is there any reasoning that should make it obvious to me ? (I'm guessing A C D A is the correct one, because everyone plays that on youtube )

Thanks in advance !

And in order to somewhat broaden the topic - what do you do when there are varying notes in different editions of a piece ?

I have Mikuli and he has ACDA. Let me guess...is the ADFA version Klindsworth? It doesn't make any sense to me.

Yep it's Klindsworth - is it known to be untrustworthy ? I've learnt most of Op. 10 with it, you're getting me scared there...
ACDA makes sense I guess ; but I'm so used to the other one... Luckily most pianos I get to play on are so bad that one can hardly hear anything in the basses at that speed (even without the pedal)... Even when it is I who play, I'm not sure I hit the good keys ;D (you know, those nameless uprights on wooden floors where almost every bass key sounds the same dull crappy tone - good luck having a cantabile melody in that register).
Thanks for the Mikuli's Terez ; a friend of mine has an edition for students anotated by Cortot, and he says the same.

Klindsworth is horrible. He probably changed the notes because he thought it sounded better that way. I'm thinking about trying to contact IMSLP to request that they remove that edition. There's no sense having it up there when there are better editions available for download. Aren't there?

Well it can't hurt to have there as a reference (it has some weird fingerings that can be useful sometimes) ; but IMSLP definitly needs some kind of comment system so you can report errors. The notation system is nice, but to me it focuses more on the quality of the scan and overall aspect of the sheet, than on the notes themselves.

Anyways now I must check other editions for mistakes in what I've learnt... Good excuse to give the Etudes a spin I guess (plus with the anniversary having decent Chopin in your repertoire is always a plus ! Especially since that's pretty much all I know, apart from maybe 2 or 3 preludes and the finale of the 3rd sonata).