When casting, sometimes my left hand will just not do anything, or will only cast for about a half a second before doing nothing. Other times my hands will go into a a "Hadoken" street fighter form and hit for harder. Other times both spells go of and my left side will just stop. This is even more buggy when I am actually under attack and my left will basically do nothing. I can always cast on my right hand however.

I then tried to switch up the mouse buttons, but then it is my Right hand that is not properly working. Has anyone had this happen?

http://www.gamesas.com/index.php?/forum/180-pc/

sounds like a problem with your mouse. Did you try a different mouse?

That is what I thought at first until I switched up the buttons on controls. It seemed to work when i first got dual casting however, then progressively got worse as I kept playing.

Yeah but when you switched the mouse buttons, what happened is exactly what you would *expect* to happen if the mouse was having a problem - the hand that wasn't working started working fine, and the other hand which had been working stopped working. E.g. one of the mouse buttons is not working right and when you switch hands, the "new" hand associated to that button stopped working.