Can't delete a power

[grc001]

Hey there,
Not sure this is the right place for this question but here goes anyway!

I decided to change powers for the character I'm building and I don't want the first power in an array (that basically starts the whole array) because there is no 'X'available. I've checked and I'm sure the power is not attached to another power that I can see.

Any advice?
Thanks in advance,
Graham C.