Spam and Virus Delivery tool doesn't update

[Ubuntu]

The Server Configuration -> Spam and Virus Delivery tool doesn't seem to be doing anything. I made some changes and clicked save, but when I came back to the tool the previous values were still set.

Also, I noticed that the timestamp on the /etc/webmin/virtual-serer/procmail/DOMAINID file was updated, but the contents didn't change.

Finally, the default in that file is to deliver spam to $HOME/Maildir/.spam, but the default in the web UI is to deliver normally.