Exponents in expression?

Hi everyone:

I'm having trouble with exponents in expressions. The following does not work, and returns the value 7 instead of 25 (seems to want to add the 2 as if simply ignoring the carat:

task x
 keys space
 set $x 5
 set $square expression $x ^ 2
 save $x
 save $square

block x
 tasklist
   x 1
 end

blockorder
 x

Nor does this, still returns 7:

set $square expression $x ^2
This just results in a compile error:

set $square expression $x ** 2
This works:

set $square expression $x * $x
But would become cumbersome for large exponents. 

Anyone figured this out?