Update problem with Debian Perfect Server

[Blasted]

Hi all,

I've been running a couple of Debian VM's for a couple years based on the Perfect Setup 4.0 http://www.howtoforge.com/perfect_setup_debian_etch

They've been running perfectly (heh) but probably due to the fact they are underutilised and I don't fix what isn't broken (read as: I haven't been applying patches ). I'm planning on using them more seriously in the future and have been (trying to) update them to the latest patch levels.

I did an apt-get upgrade which got so far, but now will not go any further than -

The following packages have unmet dependencies:
dpkg: PreDepends: libc6 (>= 2.6) but 2.3.6.ds1-13etch8 is installed
PreDepends: xz-utils but it is not installed
E: Unmet dependencies. Try using -f.

I've poked around the internets and haven't been able to find a resolution, I've tried to update it using aptitude also, but get this -

Preconfiguring packages ...
/usr/bin/dpkg: /lib/tls/i686/cmov/libc.so.6: version `GLIBC_2.6' not found (required by /usr/bin/dpkg)
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install. Trying to recover:
dpkg: /lib/tls/i686/cmov/libc.so.6: version `GLIBC_2.6' not found (required by dpkg)
Press return to continue.

Debian_version reports I'm running 6.0.1 and a uname -a returns -
Linux www1 2.6.18-6-686 #1 SMP Fri Dec 12 16:48:28 UTC 2008 i686 GNU/Linux

My sources.list looks like this -

###### Debian Main Repos
deb http://ftp.nz.debian.org/debian/ squeeze main contrib
deb-src http://ftp.nz.debian.org/debian/ squeeze main contrib

###### Debian Update Repos
deb http://security.debian.org/ squeeze/updates main contrib
deb http://ftp.nz.debian.org/debian/ squeeze-proposed-updates main contrib
deb-src http://security.debian.org/ squeeze/updates main contrib
deb-src http://ftp.nz.debian.org/debian/ squeeze-proposed-updates main contrib

Also, I found a similar problem on LQ, but it ended badly, I have a snapshot and backups but need some guidance on which way to go...

Thanks,
B