auto attacking with spells on changed hotkeys?

was playing with my witch character and was in the 2nd act on normal difficulty. running around and getting kills as normal until i ran into a rare named monster. spammed frost wave and cold snap on it and after it was dead, the game continued to use cold snap as if it was an automatic attack function, drained mana and continued when the character had enough to cast.

leaving the area and returning fixed the issue.

i had changed my skill keys to the numerical pad for use on my Razer Naga mouse. (also, my keyboard is a Logitech G19, if that helps?) both drivers are up to date.