get Smartlist to work

I try to make the Smartlist to work with qmail.

qmail is working fine.

Upon sending a mail to a Smartlist list, nothing on the list side is 
seen, and the /var/log/maillog shows:

Aug 11 15:47:39 db3 qmail: 1250023659.091760 new msg 25821488
Aug 11 15:47:39 db3 qmail: 1250023659.091807 info msg 25821488: bytes 1826 from <tom@somedomain$
Aug 11 15:47:39 db3 qmail: 1250023659.093674 starting delivery 50: msg 25821488 to local mylist$
Aug 11 15:47:39 db3 qmail: 1250023659.093993 status: local 1/10 remote 0/20
Aug 11 15:47:39 db3 procmail[18029]: Error while writing to "log"
Aug 11 15:47:39 db3 sendmail[18034]: n7BKldCE018034: from=alias, size=0, class=0, nrcpts=0, msg$
Aug 11 15:47:39 db3 qmail: 1250023659.109784 delivery 50: success: flist:_Strange_group_or_user$
Aug 11 15:47:39 db3 qmail: 1250023659.109851 status: local 0/10 remote 0/20
Aug 11 15:47:39 db3 qmail: 1250023659.109873 end msg 25821488

although I had my list permissons as:

drwxrwxr-x 11 slist slist 4.0K Jul 31 13:30 slist
drwxr-sr-x  8 slist slist 4.0K Aug  5 19:25 slist/mylist
-rw-rw-rw-  1 slist slist    0 Aug  5 19:25 slist/mylist/log

What could be wrong?

Zhiliang