Sorry to dredge this up but as Mandrake 9 is still in beta I'm reminded of few points in theregister "review" of Mandrake 8.2 (http://www.theregister.co.uk/content/4/25160.html).
In it the reviewer which mentioned how a reinstallation was necessary after a failed kernel compile. I had my own little spin on this myself when I downloaded the stock kernel and compiled my own "bad" kernel. If this has changed in 9 then my apologies but in 8.2 the entries in lilo.conf for the mandrake kernels all used the vmlinuz symlink which is libel to change if a new (non mandrake kernel) is compiled thus causing grief if this kernel compile goes wrong. I really feel that the entries in lilo.conf should use the full kernel image name to guard against this (or perhaps some special mandrake kernel link). Concerning the .config file complaint (The config file had almost no relationship to the previously installed system.) - since I don't recompile the mandrake kernel I can't really comment on this. Is the simple firewall wizard back in the default install in Mandrake 9.0? I had to install by hand on 8.2... -- Sitsofe | http://sucs.org/~sits/