No audio after exporting from AE through Media Encoder

Hi. I'm trying to export a file from AE CC (2014)  with Media Encoder but there is no Audio on the export. I need to use Media Encoder because I want the file in H.264. The Audio box is checked in the settings window. I also tried exporting a lossless version with the Render Queue and that export did have Audio. Any Advice?

Much thanks,

Sam