Page Settings scaling inconsistency

1. Open attached score (saved in 1.2, but created in a version earlier).
2. Compare 1.2 and 2.0.

Expected result: One bar per line (as displayed in 1.2).
Actual result: First two bars are in one line.

3. Open 'Page Settings'.
4. Click once on 'Up' in 'Scaling'.
5. Click once on 'Down'.

Result: Preview appears different compared to before it was changed, despite the same measurement.

6. Click once on 'Down'.
7. Click once on 'Up'.

Result: Preview appears different compared to before it was changed, despite the same measurement.

Using MuseScore 2.0 Nightly Build (5547) - Mac 10.7.3.

(Credit: 'Scenes From An Italian Restaurant' - Billy Joel)