Hello again, I've tracked the problem down.
Apparently the CentOS crontab sets predefined values for crucial
environment variables such as $HOME
Also it runs the script from the / directory, instead of from the
user's home directory, and this causes the script to fail because it
doesn't find the backup_vmware.conf script.
But you can overcome this problem by preceding the script command with
some instructions, separated by semicolons, in the crontab entry:
# runs backup_vmware script to backup the Virtual Machines every night
0 22 * * * root cd /root; source /root/.bash_profile; /root/
-D -s hot -f lzop
I've tried this and it works ok.
Hope this fixes your problem!