[Exim] amavis and exim4, exit code 13 ....FAIL

hi there,

i downloaded amavis 0.3.12pre8 and installed it in /home/Amavis/
(/home/Amavis/var)
i have successfully configured it to use the oav scannerdaemon
listening
on localhost
(scannerdaemon is installed in /home/openAV - working fine)

i also added routers and transport to exims configfile

ok, restarting exim, and sending a mail from an external host says:

'amavis transport returned 13 from command /home/Amavis/sbin/amavis'
and

the message get frozen :((

as i figured out, 13 means 'permission denied' i think
what is the problem? i have make chmod -R ugo+rx to /home/Amavis for
testing, still exiting with code 13....

thanks for any kind of help :-)

volker