Fantasie Impromptu - 2 versions?

[Petter]

I know someone brought up this up before.
 There´s supposed to be 2 editions and I noticed now how the scores available for download here differs in the bass accompaniment. The version available from the pianostreet eidtors has a slightly easier bass pattern. Bar 7 has a F# instead of D# and bar 12 has a B instead of G#.

What´s the reason behind this mix up? The pianostreet versions claims to be urtext of the first version. I´m confused. 

[odd_wanderer]

I don't know what edition the Piano Street library has but:

Chopin apparently made a few versions of that impromptu.

The version most commonly played is his first draft, published by Fontana, a friend of Chopin who also gave the piece its name (Fantaisie Impromptu).

However, Chopin produced a finished version in 1835. It is a bit more complicated, but I like it better. Its most obvious feature is a chord played right before the end of both descending right-handed chromatic scales (bars 36 and 114 in the Wiener Urtext edition).

It is also worth noting that Chopin had multiple publishers and that discrepancies exist between their editions.

Here is Rubinstein's performance of the final work (published by Wiener Urtext I think):

By the way, some people say that they dislike this impromptu because it sounds unfinished. The version that they play and hear usually is.