Error initializing audio stream

Hi guys,
I’m using the VSE to create a movie using an image sequence and overlaying separate audio. Worked perfectly fine this morning. However, after installing an update I now get the “error initializing audio stream” message.

I’m using version 2.62 installed on linux. I am trying to output to MP4 with AAC audio, although no other setting seem to work either. Any thoughts on how to fix this?

I went back to render using blender-2.57b-linux-glibc27-x86_64. Worked fine.