php & xvfb gives xauth command not found

Hello, I am using the program "njplot" in a script, an unfortunately it reqires a minimal X environment. So I am executing this programm by: $test=exec("/usr/bin/xvfb-run /usr/bin/njplot -psonly testfile 2>&1"); echo $test; As a result I get: "xvfb-run: xauth command not found; exiting." The strange thing is, that this command did work properly, but got broken some days ago. The script is being executed on a debian woody server. On the other side, the command "/usr/bin/xvfb-run /usr/bin/njplot -psonly testfile 2>&1" is working properly when being executed manually. Does anyone by chance know how to resolve this problem? Best regards, Daniel Struck -- Retrovirology Laboratory Luxembourg Centre Hospitalier de Luxembourg 4, rue E. Barblé L-1210 Luxembourg phone: +352-44116105 fax: +352-44116113 web: http://www.retrovirology.lu e-mail: struck.d@retrovirology.lu