security-control.sh: COF: command not found

Dear list, for a few days now I am getting the above message whenever I run /usr/lib/secchk/security-control.sh. I have tried to find out which command cannot be found but I haven't succeeded so far. I can remember changing anything in my setup. All the programs called from security-control.sh seem to be there... Has anyone seen this message before? Where does it come from? Any ideas where I should look for problems? security-control.sh does still give me output when run by hand but I'm not getting any mails when it is run by cron. Any help will be appreciated. Frederik