Hello! I am using Moyea SWF converter. My swf plays the sound effects great, but when I convert it to hd, the sound effects doesn't work. I'm using high or medium qual for vid and audio. also my .fla bitrate is kbps and the convert stereo to mono checkbox is unchecked

Use swivel instead. http://www.newgrounds.com/wiki/creator-resources/flash-resources/swivel#wiki_toc_2
Works perfectly fine and it's free.