trouble with mp3 players

[ettore2379]

Hi to all,
I tried for a few days to use Hero instead of my iPod touch to listen some music. I tried native player of the phone and mixZing app with a 16GB SD card. I noticed, sometimes, at the beginning of songs, for a few seconds, music "jump". Anyone tried this thing???
I made also a little search in the web about other players. I found Tune Wiki (interesting...but he didn't use album cover I already have!!!) and Diggin. On the web a lot of people talk a lot about Diggin...but I can't find it in marketplace!!! Why???

Thanks a lot.