locate not working

[Doctor Who]

I installed 'locate' from MacPorts not realizing that it was part of
my Leopard install.  The locate command was working for me at one
point, but now it returns no results. :-(

tbook:~ who$ locate locate
tbook:~ who$ locate bash
tbook:~ who$ locate ls

I have run 'sudo /etc/periodic/weekly/310.locate' to update the
database for locate.  The 'locate' being run is:

tbook:~ who$ which locate
/opt/local/bin/locate

which appears to be the MacPorts version.  How can I get either this
locate working or start using Leopard's locate command by default?

Thanks.