[music scope - 7digital] Can't see other peer categories, until after select "All categories"

[Wenfang Si]

arale device, r170, ubuntu-touch/vivid-proposed

Steps:
1. Swipe to "Music" scope
2. Tap on "New albums for 7 digital" and enter 7 digital scope
3. Current category is "New releases"
4. Tap on "New releases" to show the list, and not seeing other categories (Top albums & Top tracks)
5. Select "All categories" and then tap on "All categories" again to show the list
6. Now there are 3 items "Top albums, Top tracks, Genres" under "All categories" group

Expect:
In step4 the list should include all items as in step6

[Evan Wang (wsy324)]

I can reproduce this issue on Arale/vivid with r183.