Anotherone having problems w/ audio!

Had the entire project set for burning into DVD. Client requested additional
material be added into the project. Went back to PP 2.0, did the adjustments and
exported them to AVI and imported them into the Encore Project. Had a little bit
of problem replacing the old footage, deleted it and added the new one. It was
not synching very well (Later on I found the replace footage option).

My problem now is that of the 7 different AVI's that I have on the timeline 2
only playback audio in the first minute and then it's gone, video is ok. Tried
changing from Dolby to PCM adjusting, transcoding, deleting DIVX from CPU,
burning into a DVD just one of the clips and still the same problem.

Did the whole thing all over again on a fresh new project, importing the
materials (which by the way, the AVI's playback is good on Windows Media Player)
and no go. Checked the PP 2.0 Project timelines, and the sound was still there
so I did not encode with a muted audio track.

Now I'm exporting the whole project in one single timeline on PP 2.0 to see if
the audio problem gets bypassed when I import it into Encore.

Latest application installed (tryout Cineform HD, just expired 15 day trial).

Any suggestions will be appreciated.

(Level of Knowledge: Novice)