I still use the free version only, by and large it's pretty good.
But every so often, on my phone, it skips the first second or two of a track.
It doesn't do it all the time, but when it starts doing it, it does it consistently for a spell.
I've switched between the various playback options "gapless" "none" etc.
It may be just my crappy phone, which I'm stuck with until contract's end in October, but any suggestions?