Error upgrading squeeze to wheezy

[Andrew Wood <a.j.w@me.com>]

Im encountering the same error on several machines when doing apt-get 
update  apt-get upgrade apt-get sist-upgrade from a clean install of 
squeeze to wheezy.

The error is

E: Could not perform immediate configuration on 'libgstreamer0.10-0'. 
Please see man 5 apt.conf under APT::Immediate-Configure for details. (2)

the only reference I can find to anyone having a similar problem is here:
http://old.nabble.com/Bug-645713%3A-fails-to-upgrade-a-default-GNOME-desktop-installation-from-squeeze-%E2%86%92-sid-td32671887.html

but it just gets dismissed.

Anyone any suggestion as to whats wrong?