Hi All,
We are aware of this bug and have already done the fix for this in the next patch update.
I have already covered this problem on another thread that was posted here
Please keep on eye on the forms for more information when the patch comes out with this bug fix.
I just had this happen to me in the middle of an awesome arena day. The cursor moves around and I can move gems to match them but I cannot select any of my magic spells. The cursor just changes to the hand and nothing happens.