pinning not working

[Luis Finotti <finotti.deb@gmail.com>]

Hi,

I am trying to install KDE 4.2 on lenny.  (I made backups and am aware
that things might go bad.  I wanted to try it anyway.)  So, I followed
theshttp://pkg-kde.alioth.debian.org/experimental.html#contente
instructions:

http://pkg-kde.alioth.debian.org/experimental.html#content

Here are the relevant files:

-------------------------
t60[~]$ cat /etc/apt/sources.list
# Security
deb http://security.debian.org/ lenny/updates main contrib non-free

# Main
deb http://ftp.gtlib.gatech.edu/debian/ lenny main contrib non-free
# deb http://sunsite.utk.edu/ftp/pub/linux/Debian/ lenny main contrib non-free

# Sid -- KDE4
deb http://ftp.us.debian.org/debian sid main contrib non-free
# deb http://ftp.gtlib.gatech.edu/debian/ sid main
# deb http://sunsite.utk.edu/ftp/pub/linux/Debian/ sid main contrib non-free

# Experimental -- KDE4
deb http://ftp.us.debian.org/debian experimental main contrib non-free
# deb http://ftp.gtlib.gatech.edu/debian/ sid main
# deb http://sunsite.utk.edu/ftp/pub/linux/Debian/ sid main contrib non-free

# Multimedia
deb http://www.debian-multimedia.org lenny main

# Volatile
#deb http://volatile.debian.org/debian-volatile lenny/volatile main contrib

t60[~]$ cat /etc/apt/preferences
Package: *
Pin: release a=lenny
Pin-Priority: 900

Package: *
Pin: release a=sid
Pin-Priority: 300

Package: *
Pin: release a=experimental
Pin-Priority: 101

------------------------------

Before installing KDE 4.2, I decided to check if pinning would work,
but "aptitude dist-upgrade" (before installing anything from Sid or
Experimental) wants to upgrade most (all?) packages:

------------------------------
t60[~]$ sudo aptitude dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Reading extended state information
Initializing package states... Done
Reading task descriptions... Done
The following packages are BROKEN:
  libavcodec52
The following NEW packages will be installed:
  consolekit{a} dnsmasq-base{a} esound-clients{a} geoip-database{a}
gstreamer0.10-ffmpeg{a}

[snip]

571 packages upgraded, 86 newly installed, 24 to remove and 0 not upgraded.
Need to get 667MB of archives. After unpacking 165MB will be used.
The following packages have unmet dependencies:

[snip]

-----------------------------------

Can any one shed some light?

Thanks in advance,

Luis