Pinning question

[Rich B <bpclists@osg.saic.com>]

One of my servers is running stable, but I've added Unstable to my 
/etc/apt/sources file, and in /etc/apt/preferences I put:

  Package: *
  Pin: release stable
  Pin-priority: 900

  Package: *
  Pin: release testing
  Pin-priority: 500

  Package: *
  Pin: release unstable
  Pin-priority: 100

Now, when I do an apt-get dist-upgrade I'm told:

  The following NEW packages will be installed:
    gcc-3.3-base initscripts

What did I do wrong? I thought my Pin-prioritys would prevent anything 
from upgrading to Sid unless I explicitly asked for it.

Rich B.