No Audio in After Effects Composition.

When i import clips into after effects they have sound and when you play them they work find. But when i put the clips into an after effects composition they don't have any audio, not even a waveform. I have done most of the basic stuff and it's not a RAM preview issue i don't think.

I have tried using clips that have worked fine in the past and they lost their sound when they are imported into a comp. I have tried using wav formats for audio and they don't work either. I have this problem when using after effects cs6 and cs5 on my mac. I even tried installing the trial on a windows partition and this did not work either and i had the exact same problem.

Please help.
Thanks.