Never mind, I've found a mod called Light Control from here:
May wanna add it to Curse Voice, I see his other mods there.
Using light control I've set minecraft:fire to a light level of 9 instead of its original 15 and cursed earth needs a light level of 10 or above to set itself on fire.
Makes things interesting as i can use light to push back against cursed earth to expand my territory without all hell breaking loose. :)