The audio exports fine, but when I open the file there is just silence. I've tried different export formats, and different media players. It has worked flawlessly before, and if I try to export my older projects it works fine as well, so it has to be something with my newer projects. I use Windows 7 Home Premium 64.
Edit: I got it to work now, it seems you have to put the audio output to StMast (Stereo Master) instead of your speakers, at least that worked for me.