[CentOS] Amavisd start

This is CentOS 6. Why can it be that when I try to run
	/etc/init.d/amavisd start
... I get this error:
Starting Mail Virus Scanner (amavisd): Config file "/etc/amavisd.conf" 
is inaccessible: Permission denied, at /usr/sbin/amavisd line 2085.
[FAILED]

But when I use sh:
	sh /etc/init.d/amavisd start
...it starts ok.

This is connected to the fact that my amavisd.conf is from another 
machine (CentOS 5). If I replace amavisd.conf with the default conf 
(that came with yum install amavisd-new), the starting problem goes away.

I would like to debug this, but I don't know where to look.

- Jussi