There is a sound glitch when rb starts to play sound ... doesn't matter whether it's normal music play or sound from rockboy.
I noticed a strange behavior with loading a cover image of a album.
On my r0 I use a folder hierarchy for my music which looks like: [artist]/[album].
In the music files itself there is no cover image - I have a cover.jpg (max. 640x640 Pixel sized) for each album folder. Rb loads the cover.jpg the first time a file from the album is played, but after 2-5 files played from the same folder (which means same album) rb forgets the cover and reloads it.