The only problem with the health/weapon energy(/xp) codes I made is, as they are hack of the 'display' routine, they won't work if your health/weapon energy(/xp) aren't displayed on screen (as the routine won't be called). I'm not sure if that can happen tough (apart when being on the pause menu, or looking at the map - but I assumed enemies couldn't move/dammage you during that time, maybe I was wrong ?), so maybe it's your problem cracker ?
Anyway if you can provide details on when your death happened, I'll try to make something different.
@754boy : thanks for reporting codes are working for you

Edit @cracker : after a second though, that seems wrong. I mean, you're implying the codes had an effect (visual infinite health), but you still died... So I only see two theorical explanations for now :
You take too much dammages over time (ie. too many ennemies hit you before the code could replenish your health).
You took a dammage that one-hit killed you (either because it was meant to one hit kill you, or because the dammage was above your max health).
Right now my codes copy the max health and paste it to the current health. I'll change (not now, in some hours) them to overwrite the max and current health with a very big number, to see if that stops you from diying (it will resolve the dammage over time and the dammage above max health problem ; however, if a dammage is meant to one hit kill you that might now prevent it).