Version:           2.1.1 (using 4.2.2 (KDE 4.2.2), Kubuntu packages)
Compiler:          cc
OS:                Linux (x86_64) release 2.6.28-13-generic

The interface for generating dynamic playlists is, frankly, incomprehensible.

It seems like a fundamental truism that, since the rubric for "Proportional bias" is "match a certain portion of the playlist to a value", then if one sets the slider for a filter to X%, then X% of the resulting playlist will be selected by that filter.

But that's not at all what happens. Each filter can be set to any value, so that the sum, instead of being 100% can be anything... and it's completely opaque what the final contribution of each filter will be to the playlist.

One can imagine several things that the underlying code *might* do if the sliders add up to something different than 100%, but the point is that:
  (a) there's no way to know which of those possibilities the code actually implements (and in fact, so far all my guesses have been wrong... I still haven't figured out what the code does, despite trying rather hard to deduce the underlying algorithm from the output playlists); 
  (b) it's simply completely unintuitive to have a total add up to anything other than 100%.