[NiteWave]

my local test not empty, show " /usr/bin/convert" correctly:

:: [echo $PATH]
/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

:: [ls /usr/bin/which]
/usr/bin/which

:: [ls /usr/bin/convert]
/usr/bin/convert

:: [/usr/bin/which --version]
GNU which v2.16, Copyright (C) 1999 - 2003 Carlo Wood.
GNU which comes with ABSOLUTELY NO WARRANTY;
This program is free software; your freedom to use, change
and distribute this program is protected by the GPL.

:: [/usr/bin/convert --version]
Version: ImageMagick 6.2.8 02/22/12 Q16 file:/usr/share/ImageMagick-6.2.8/doc/index.html
Copyright: Copyright (C) 1999-2006 ImageMagick Studio LLC

:: [/usr/bin/which convert]
/usr/bin/convert