You know this bug dates back to the Savant Prestige Classes days...
... yet not fixed .
Max caster level increases (resulting from destiny abilities, savant prestige classes, savant tod set bonuses) do not correctly increase the cap for Niac's Biting Cold (arcane lv.5) and Eledar's Electric Surge (arcane lv.5): so these spells do not actually do more damage but they do the same with and without the max caster level increases.
This kind of problem extends also to other spells. Probably someone could enumerate them better than me but regarding the ones i use mostly i can assure that this mechanic don't work with: Shocking Grasp (arcane lv.1), Electric Loop (arcane lv.2), Ice Storm (arcane lv.4).
It would be extremel helpful... and i will construct a statue in Lord's March Plaza in Stomreach to the programmer that will free the poor sorcerers and the other arcane casters from this awful yet omnipresent bug!
Please consider helping us super-mega-uber-knower_of_everything-most_merciful SqueakOfDoom,