background processin do not work

same file can upload in real time and batch

2007-10-06 10:39:10 Upload Finished

2007-10-06 10:39:10 Running: /usr/bin/php -q /home/internev/public_html/convert.php 131 > /dev/null &

2007-10-06 10:39:10 Starting Background video conversion - 131

2007-10-06 10:39:10 Video (131) Conversion starting...

2007-10-06 10:39:10 File: /home/internev/public_html/video/flvcamtasia_6.flv

2007-10-06 10:39:10 -------------------------------------------------------------

2007-10-06 10:39:10 INSERT INTO video SET
UID='2',
title='back',
description='back',
keyword='back',
channel='0|1|0',
addtime='1191681550',
adddate='2007-10-06',
vkey='156642246',
type='public',
active='0',
approve='1'

2007-10-06 10:39:10 -------------------------------------------------------------

2007-10-06 10:39:10 Video id: 108

2007-10-06 10:39:10 Calling ffmpeg-php -> ffmpeg_movie()

2007-10-06 10:39:10 Get video duration - START

2007-10-06 10:39:10 Get video duration - END

2007-10-06 10:39:10 DURATION: 17

2007-10-06 10:39:10 Create Thumbnail - START

2007-10-06 10:44:06 Upload Finished

2007-10-06 10:44:06 Running: /usr/bin/php -q /home/internev/public_html/convert.php 132 > /dev/null &

2007-10-06 10:44:06 Starting Background video conversion - 132

2007-10-06 10:44:06 Video (132) Conversion starting...

2007-10-06 10:44:06 File: /home/internev/public_html/video/flvcamtasia_7.flv

2007-10-06 10:44:06 -------------------------------------------------------------

2007-10-06 10:44:06 INSERT INTO video SET
UID='2',
title='test 7',
description='test 7',
keyword='test',
channel='0|1|0',
addtime='1191681846',
adddate='2007-10-06',
vkey='2088837742',
type='public',
active='0',
approve='1'

2007-10-06 10:44:06 -------------------------------------------------------------

2007-10-06 10:44:06 Video id: 109

2007-10-06 10:44:06 Calling ffmpeg-php -> ffmpeg_movie()

2007-10-06 10:44:06 Get video duration - START

2007-10-06 10:44:06 Get video duration - END

2007-10-06 10:44:06 DURATION: 17

2007-10-06 10:44:06 Create Thumbnail - START

any ideas

Than you for help