failure in importing with repos that are similar: "WARNING: multiple ocurrences"

[cong06]

Binary package hint: apt-proxy

When importing, using debug 9, the error appears:
"WARNING: multiple ocurrences"

This means, I assume, that there are two repositories, (security.ubuntu.com and archive.ubuntu.com) that could share the same package.

Now I would hope that that would mean that the package would copy the debian package into both (local) repositories so that either one could give the package when it's asked for.
Instead it seems it picks one randomly, and when the other repository is asked for the package, apt-proxy has to go out and download it to the other one, even though it's already on the computer.

A quick fix, even though it's very messy, is to keep only one of the two conflicting backends uncommented, restart, import, and then switch.

/etc/apt-proxy/apt-proxy-v2.conf is attached

Ubuntu 9.04
apt-proxy:
  Installed: 1.9.36.3+nmu1ubuntu1
  Candidate: 1.9.36.3+nmu1ubuntu1
  Version table:
 *** 1.9.36.3+nmu1ubuntu1 0
        500 http://localhost jaunty/universe Packages
        100 /var/lib/dpkg/status
     1.3.7 0
        500 http://localhost stable/ Packages