Some sound clips are not playing while other sound clips play fine, any suggestions?

I am trying to deliver a trailer for my movie to a distributor, everything was fine until this morning, when I tried to play the trailer and some sound clips were being heard while others did NOT play even though I could see them going in the meter.

To test it out, I copied and pasted one of the sound clips that did work next to one another and the original played but the duplicated clip did not.

Now, keep in mind the trailer is only a 3 minute HD (shot on a Panasonic HVX), and I had 18 tracks of audio. I mixed them down and exported them using Quick time conversion and making the other clips inaudible and exported the audible tracks clips as AIF files. They are now 6 tracks.

1. Dialogue L
2. Dialogue R
3. Foley L
4. Foley R
5. Music L
6. Music R

I can hear all of the sound clips play individually in FCP, the issues seem to stem from when I put them on top of each other in the timeline, then I can only hear the first dialogue track, the other 4 tracks I cannot hear even though I see activity in the audio meter.

I am able to hear all the files when I open them in Quick time.

I can see all the tracks were exported perfectly in Soundtrack Pro ? it does play all 6 tracks in that software together, just not FCP

I can see the audio lines in the timeline on the clips in FCP and the meter, I just don?t hear the sound

So far I have tried:

1. Trashing my prefs
2. Adjusting systems settings
3. Adjusting user preferences to 20 tracks instead of 8
4. Making sure Audio playback quality is in low (faster)
5. It is currently in stereo monitoring L+R under ?audio inputs?
6. Changing RT to unlimited
7. To re-export the clips and re-import them
8. Exporting and re-importing as wave files
9. Restarting my computer
10. Restarting FCP
11. I opened in a new sequences and laid down the tracks, it didn?t help
12. I opened up a new project and laid down the tracks, this didn?t help either

I have 159 gigs left on my 1 terabyte external drive, a western digital 0 raid, which I am working off of.

Any advice is greatly appreciated. I?m sure I am not the only one this has happened to at some point. Thank you.

Specs:

FCP 7.0.2
Version 10.6.4
Mac Pro 1,1
Processor: 2 x 2.66 Ghz Dual Core Intel Xeon
Memory: 8 GB 667 MHz DDR2 FB- DIMM
Graphics card: ATI Radeon HD 3870

Details about my project:

FCP Settings in 720 24p timeline
1 project
19 sequences
18 layers of audio
1 layer of video

Have you check to see if your tracks 3 through 6 are assigned to outputs 1 & 2?

That, or hit option 6 for the audio mixer, and make sure the Stereo Mixdown icon is depressed. It is the second button on the main output bus:





www.strypesinpost.com

Yeah, what is your sequence setting for audio? (which is what these guys are working around) Possibly you've got a sequence audio setup default that is pumping audio out to speakers you don't have attached to your system