The original source was checked with Mediainfo, that's where the stats I posted came from. Here is the complete output, copy/pasted from the text output:
General
Complete name : C:\AniMix Project - Full.512x384.XviD.avi
Format : AVI
Format/Info : Audio Video Interleave
File size : 692 MiB
Duration : 1 h 0 min
Overall bit rate : 1 612 kb/s
Writing application : Nandub v1.0rc2
Video
ID : 0
Format : MPEG-4 Visual
Format profile : Simple@L3
Format settings, BVOP : No
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : DX50
Codec ID/Hint : DivX 5
Duration : 1 h 0 min
Bit rate : 1 472 kb/s
Width : 512 pixels
Height : 384 pixels
Display aspect ratio : 4:3
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.312
Stream size : 632 MiB (91%)
Writing library : XviD 1.0.0 RC4 (Hola) (UTC 2004-04-05)
Audio
ID : 1
Format : MPEG Audio
Codec ID : 55
Codec ID/Hint : MP3
Duration : 1 h 0 min
Bit rate : 128 kb/s
Channel(s) : 2 channels
Sampling rate : 44.1 kHz
Compression mode : Lossy
Stream size : 54.9 MiB (8%)
Alignment : Split accross interleaves
Interleave, duration : 26 ms (0.63 video frame)
Interleave, preload duration : 500 ms
And here is the output for the file created by Premier:
General
Complete name : C:\Users\Chris\Videos\Sequence 01.m2v
Format : MPEG Video
Format version : Version 2
File size : 2.93 GiB
Duration : 1 h 0 min
Overall bit rate mode : Variable
Overall bit rate : 6 997 kb/s
Video
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings : BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=15
Duration : 1 h 0 min
Bit rate mode : Variable
Bit rate : 6 997 kb/s
Maximum bit rate : 8 000 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Scan order : 2:3 Pulldown
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.844
Time code of first frame : 00:00:00:00
GOP, Open/Closed : Closed
Stream size : 2.93 GiB (100%)
Yes, DVD is 29.97 but that is why I am using the MPEG-DVD format specifically when exporting from Premier.
The audio seems to go out of sync gradually. It is fine in the beginning, slightly out in the middle to the point of being noticeable, and very noticeable at the end. And yes this does happen in encore preview.
Speaking of which here are a few screenshots of what encore does to the audio and video.
First is the list of assets and the timeline before anything is added to said timeline.
Here is the same area after the video is added.
Here is the end of the timeline with the audio added. Notice that it is a good 1 second shorter than the video.
On a side note I just checked the video output file from Premier along with the audio from Audacity combined using mplayer. The sync problem exists there as well. So the question becomes is this an issue with the audio or the video?