MP4 Video won't load at all

I tried watching a documentary and the video files just start to load, but then the progress bar stops about 1/4 of the way through and never continues. I've confirmed that the video files won't load in Quicktime in OS X either but they do play just fine in VLC. Here is the mediainfo output for one of the files:

General
Complete name : /Volumes/Mac HD/Users/mwinstone/Downloads/The Nazi's - A Warning from History/1 - Helped Into Power.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42
File size : 985 MiB
Duration : 48mn 31s
Overall bit rate : 2 839 Kbps
Encoded date : UTC 2010-11-05 18:32:59
Tagged date : UTC 2010-11-05 18:35:22

Video
ID : 2
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : Yes
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : 20
Duration : 48mn 31s
Bit rate mode : Variable
Bit rate : 2 568 Kbps
Maximum bit rate : 5 397 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.248
Stream size : 891 MiB (90%)
Language : English
Encoded date : UTC 2010-11-05 18:32:59
Tagged date : UTC 2010-11-05 18:35:22

Audio
ID : 3
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Mode : Joint stereo
Codec ID : 6B
Duration : 48mn 31s
Bit rate mode : Constant
Bit rate : 256 Kbps
Maximum bit rate : 264 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 88.9 MiB (9%)
Title : English
Language : English
Encoded date : UTC 2010-11-05 18:32:59
Tagged date : UTC 2010-11-05 18:35:22

Text
ID : 4
Format : mp4s
Codec ID : E0
Duration : 47mn 41s
Bit rate mode : Variable
Bit rate : 4 280 bps
Maximum bit rate : 94.5 Kbps
Stream size : 1.46 MiB (0%)
Title : English
Language : English
Encoded date : UTC 2010-11-05 18:32:59
Tagged date : UTC 2010-11-05 18:35:22

Menu
00:00:00.000 : Chapter 1
00:08:50.160 : Chapter 2
00:13:22.080 : Chapter 3
00:24:19.240 : Chapter 4
00:32:21.040 : Chapter 5
00:38:57.320 : Chapter 6
00:48:33.000 : Chapter 7