Bug#177680: unable to downgrade using pin priority > 1000

[Knoppix User <nobody@nowhere.com>]

Package: apt
Version: 0.5.4
Severity: normal

My /etc/apt/preferences is:

Package: *
Pin: release a=testing
Priority: 1001

I want to downgrade from unstable to testing.  No default release is
set in /etc/apt/apt.conf.  After I apt-get update, I type apt-cache
policy <any pkg> and discover that the testing version has priority
989 (which I recognize as the default) while the unstable version
(which is installed) has priority 500.  So no downgrade occurs when
I apt-get dist-upgrade. 

Any thoughts why the 1001 priority is not being set here?

Thanks. 

-- System Information
Debian Release: testing/unstable
Architecture: i386
Kernel: Linux pvr 2.4.20 #1 SMP Tue Dec 10 02:57:13 CET 2002 i686
Locale: LANG=C, LC_CTYPE=C

Versions of packages apt depends on:
ii  libc6                        2.3.1-9     GNU C Library: Shared libraries an
ii  libstdc++2.10-glibc2.2       1:2.95.4-15 The GNU stdc++ library