Milter keeps timeing out: can't read SMFIC_BODYEOB reply packet header: Connection timed out

[JKL]

Dear everyone,

    I noticed these messages in the postfix log files from spamass-milter:

Mar 20 19:11:04 logout postfix/cleanup[19090]: warning: milter
unix:/spamass/spamass.sock: can't read SMFIC_BODYEOB reply packet
header: Connection timed out
Mar 20 19:30:47 logout postfix/cleanup[19144]: warning: milter
unix:/spamass/spamass.sock: can't read SMFIC_BODYEOB reply packet
header: Connection timed out

No messages noticed yesterday.  First message at 11.30, so something was
changed or was affected back then. However, I am unsure what. 
Spamass-milter has been removed from postfix as it was rejecting everything.

The socket is there:
# ls -l /var/spool/postfix/spamass/spamass.sock
srw-rw---- 1 postfix postfix 0 Mar 20 10:36
/var/spool/postfix/spamass/spamass.sock

The daemon is run with these options:
/usr/sbin/spamass-milter -P /var/run/spamass/spamass.pid -f -p
/var/spool/postfix/spamass/spamass.sock -u nobody -m -r 11 -i 127.0.0.1
-f -p /var/spool/postfix/spamass/spamass.sock

Any ideas?

Best wishes, S