Audio does not play on PS3 - Xvid 64 & AC3

Hello,

I am new here and I have tried searching this website for the solution for my problem but I haven't came across one yet :(. I have a movie (it's a serie and it's just this one episode) where the video and subtitles work on my PS3, but the audio doesn't. By the way - I am using a LACIE external hard drive to play my movies. I pressed the display button on the controller, and it shows: Dolby Digital, 1 ch, 32 khz. And so I checked the video info on my computer.

When I checked the video properties on my computer this is what it said:

Frame width & height: 624x352
Data rate: 1474kbps
Total bitrate: 1666kbps
Frame rate: 29fps
Bit Rate: 192 kbps
Channels: 2(stereo)
Audio sample rate: 48 khz

I checked AVIrecomp to double check and it gave me this:

Video:
MPEG-4 codec: Xvid 64
Qpel: no
GMC: no
Quant. matrix: default (H.263)
Bitrate: 1466kb/s
resolution 624x352
aspect ratio: 1.773
frames: 120618
Fps: 29.970

Audio:
Type: ac3
Bitrate: 192 kb/s
Bitrate mode: CBR
Size: 92.11 MB
Channels: 2 (stereo)
Sample rate: 48000 Hz

I am not sure why the PS3 and my PC are reading the information differently. I really need help :(