Originally Posted by
Sychotix
Its hard to say without more context. Double check all the values. ALso, keep in mind the slider means "below this value" so if you have it set to 100%, it will use it once you hit 99%. Your mana flask will stop being used (usually) if you hit 100% since your mana will be full.
Make sure all your settings are good too, like I think here is a minimum mana value too to say "Use if I have below 50 mana." I forget what the priority of all of those are... been a good while since I've looked at the code.