[Soekris] Running Debian on Soekris 4521

[Chaskiel M Grundman]

you are trying to upgrade from pre-sarge testing to current testing. You 
cannot do that.
even if that is the desired end-state, you must first upgrade to sarge 
itself.

edit /etc/apt/sources.list, and change all 'testing', to 'stable' (or 
'sarge'). Then do an apt-get update / apt-get dist-upgrade cycle. Then you 
can change back to testing (and upgrade again) if that is what you want.