Selecting items in Music Library "Song View" with keyboard is not working properly

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What steps will reproduce the problem?
1. Go into Music Library Song View
2. Select Song (with mouse)
3. Press [shift + down-arrow] (repeatly)

What is the expected output? What do you see instead?
Songs should be selected properly. 

There are several bugs:
[1] Instead on on first press, n songs are selected.
* this only occurs when the song was selected by mouse
* n does vary on which song-nr is selected, and gets bigger on bigger song-nr.
[2] Instead only two items can be selected when pressed repeatly.

Variation
1. Go into Music Library Song View
2. Select Song (somewhere in the middle)
3. Press [shift + down-arrow] once
4. Press [shift + up-arrow] once

What is the expected output? What do you see instead?
the previously selected song should be selected again. instead it selects the 
entry above.
example: when there are song 1,2,3 and song two was selected at the beginning, 
song 1 is selected after the mentioned steps. instead song 2 should be selected 

What version of the product are you using? On what operating system?
0.4.0 r0

Please provide any additional information below.

Original issue reported on code.google.com by rednam...@gmx.de on 14 Jul 2013 at 12:36

[GoogleCodeExporter]

Original comment by LucioCarreras@gmail.com on 15 Jul 2013 at 6:20

• Changed state: Accepted