Consider putting unholy toughness on the death knight. [add charisma bonus as bonus HP like alivng creature's con score]The 3.0 to 3.5 change boned a lot of monsters DR ratings, so while i am away from my book, I suspect that may have happened to the death knight. plus as a front line undead, it'll need it.

ncG1vNJzZmivp6x7prrWqKmlnF6kv6h706GpnpmUqHx0eZSeZJ2dkam1brfNop6hrF5ngniCknFm