problems with 10.04 upgrade to 12.04

[Dave Howorth]

Dave Howorth wrote:
> Marius Gedminas wrote:
>> It's a bit hard to keep track of this thread.  AFAIU at the moment
>> you've solved the lxdm problem, but the suggested workarounds for the
>> 'python-minimal preconfiguration failed' do not work.
> 
> That's my understanding too.
> 
>> *scratches head*
>>
>> *grasps straws*

I've already said that I don't understand apt and dpkg much but I'm
confused by why apt and dpkg show different things:

 # apt-cache search 'python.*minimal'
 python-minimal - minimal subset of the Python language (default version)
 python3-minimal - minimal subset of the Python language (default
python3 version)
 python2.7-minimal - Minimal subset of the Python language (version 2.7)
 python3.2-minimal - Minimal subset of the Python language (version 3.2)
 python2.6-minimal - A minimal subset of the Python language (version 2.6)

 # dpkg -l \* | grep minimal
 ii  libklibc                             1.5.17-4ubuntu1
                  minimal libc subset for use with initramfs
 ii  lxmusic                              0.4.2-2
                  The minimalist music player for LXDE
 ii  perl-base                            5.10.1-8ubuntu2.1
                  minimal Perl system
 ii  python-minimal                       2.6.5-0ubuntu1
                  A minimal subset of the Python language (default version)
 ii  python2.6-minimal                    2.6.5-1ubuntu6
                  A minimal subset of the Python language (version 2.6)
 ii  ubuntu-minimal                       1.197
                  Minimal core of Ubuntu

Why does dpkg not know about the new versions?
And what decides what should be installed?
i.e. why does apt-get say:

  python-minimal: Depends: python2.7-minimal (>= 2.7.3) but it is not
going to be installed