No sound on rendered videos

Hey all,

I'm using Vegas Pro 11 to render some videos on my TiVo Premiere. Since I only have TiVo Desktop (not Plus), I've rendered them as MPEG 2. They play just fine on my PC with Winamp and Windows Media Player. However when I play them with TiVo I get no sound.

Could it be a codec issue?

Thanks in advance :)