The best way to deal with Mandrake is synaptic. To do this:
1) [as root] urpmi synaptic
It'll probably want to pull down apt, etc etc; accept whatever it wants.
2) Go to the "easy urpmi" web site
http://plf.zarb.org/~nanardon/ and generate the info for each of contrib, updates and main (and plf, if you want).
DO NOT run the commands it tells you to (waste of time); what you're interested in is the ftp urls, and the hdlists.
DO NOT run synaptic yet, unless you want to use the Cooker repositories it comes set up with.
If you're feeling adventurous, you can generate the easy urpmi for 10.0; I have done this once (from 9 to 9.2) and with a little fiddling, it works OK. However, if you just want to keep your system up to date, generate for 9.0.
3) [As root] edit /etc/apt/sources.list
Kill all repository lines but one (leave one for example); paste/convert easy urpmi's ines into it; e.g.
urpmi.addmedia --update updates ftp://gd.tuwien.ac.at/pub/linux/Mand...ates/10.0/RPMS with ../base/hdlist.cz
should be, in sources.list, something like
rpm ftp://gd.tuwien.ac.at/pub/linux/Mand...ates/10.0/RPMS ../base/hdlist
NB that the .cz is not needed.
4) Run synaptic; go to preferences, repositories; make sure that only the 3 or 4 you added are active.
5) Click "update list". There are two stages; the first stage will probably fail (3 or 4 times); the second stage should work. If the second stage doesn't work, post your /etc/apt/sources.list file here.
6) Click "upgrade system" and then "execute".
Synaptic is 20x better than rpmdrake, although IME urpmi is about as good as apt. It's well worth switching.