[HM] Lost all audio on my movie!!!!

[ESTHER SUCRE]

I hope somebody has an answer: I had a movie I was
working on saved on my hard drive (I'm using imovie
HD) and I went on holidays. Now that I returned I
wanted to keep working on it only to find out there is
no audio. I made sure that the 3 boxes are checked to
the right of the timeline, and yes, the speakers are
on! I don't know what it could be; when I drag a clip
to the trash and then look at it while on the trash
then it has sound! If I import a new video (from my
camera) I can hear the audio while it is importing,
but when I try to play back then the audio is gone!
I'm sure it probably is something really simple, but I
can figure it out. Please Help!
Thanks in advance!!!!
E.