validrcptto.cdb patch and /etc/qmail/mkvalidrcptto.reject

Hi,

I am using dot-qmail extensions including default ones. My qmail
installation is net-qmail-10.5 patched with
netqmail-1.05-validrcptto.cdb.patch from qmail.jms1.net.

I have updated the mkvalidrcptto script to the latest version and now I
hope to use mkvalidrcptto.reject to block emails. However they are not
currently being blocked. Using cdbdump I can see that there is an entry
for the email I want blocked with an additional ':-' in
/var/qmail/control/validrcptto.cdb

but the messages aren't get blocked. What have I missed?

Thanks
Neil