Update: bg music plays after loading the same layout a second time.
Example: title (no music) -> level select (no music) -> level 1 (no music) -> player dies -> level select (music playing) -> level 1 (music playing)
Most C2 users will not experience these problems cause Phonegap build still uses 1.7, so I don't think there's the need to fix it yet. As phonegap development is like a mad's electroencephalogram there's the risk of breaking also the working 1.7 compatibility.
I'm getting really annoyed too... Their update policy is totally crazy.