show us you code if you want some help ;)
<plugin name="bgmusic_interface"
url="%ROOT%/plugins/soundinterface.swf"
alturl="%ROOT%/plugins/soundinterface.js"
rootpath=""
preload="true"
keep="true"
/>
<action name="autoplaymusic" scope="local" autorun="onstart">
playsound(bgsnd,get(global.bgmusicurl),true);
</action>
If the plugin try to automatically unlock the browsers sound playback on start using the first touch or click events,then it's only going to play once.However, when the action is executed the second time, its loop will work.I think it has something to do with autounlock.