The following:

2013-10-25 10:57:19,897 ncsa.video ERROR : [526a4e8ee4b0b062237995ea] error processing [exit code=1]

Seems stream 1 codec frame rate differs from container frame rate: 60000.00 (60000/1) -> 29.97 (30000/1001)
[mpeg4 @ 0x1708d60] Invalid pixel aspect ratio 2880/2881, limit is 255/255
Stream mapping:
Stream #0.1 -> #0.0
Stream #0.0 -> #0.1
Error while opening encoder for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height
Traceback (most recent call last):
File "VideoPreviewExtractor.py", line 181, in on_message
create_video_preview(inputfile, 'mp4', '-1:720', host, fileid)
File "VideoPreviewExtractor.py", line 74, in create_video_preview
subprocess.check_output(['ffmpeg', '-loglevel', 'error', '-y', '-i', inputfile, '-vf', 'scale=' + size, '-ar', '44100', '-strict', '-2', previewfile1], stderr=subprocess.STDOUT)
File "/usr/lib/python2.7/subprocess.py", line 544, in check_output
raise CalledProcessError(retcode, cmd, output=output)
CalledProcessError: Command '['ffmpeg', '-loglevel', 'error', '-y', '-i', '/tmp/tmpaL08BW', '-vf', 'scale=-1:720', '-ar', '44100', '-strict', '-2', '/tmp/tmpTMcBHz.mp4']' returned non-zero exit status 1

while processing the attached video file.

Note that it works with mov and other mp4 videos.