thx for the quick response i found my issue...it had to do with the javascript value conversion to a number and the default value setting.

there is no problem

Which build do you use?
I tried and it seems to work ok for me. Setting 0 sets first track in both situations - when no track was set before as playing and even when other track was playing. Tested by simple script, which just call app.player.setPlaylistPosAsync(0); on button click.
How exactly do you test it?

app.player.setPlaylistPosAsync(newIndex)

I'm trying to use [code]app.player.setPlaylistPosAsync(newIndex)[/code] to set the currently playing track in the playlist and it works unless i try to set the index to "0". Of course 1 sets the currently playing song to 2 in the list, 2 to 3, etc. So i would expect 0 to set the currently playing song to the first song.

Any thoughts on why this could be?