Duplicates in log created by queue_extra

[Nathan Harmon]

When someone sends email to a dot-qmail alias I have specified in
~alias/, the message shows up twice in the msg-log created by
queue_extra.

Question is, is there a filter to get rid of this. Or have I misconfigured.

BACKGROUND:  The qmail source was modified as instructed by
the qmail-howto (among other things). ~alias/msg-log is actually
a symbolic link which points to /var/allmail/INBOX. /var/allmail
is on a seperate fixed disk.