Why this recent change about (-1)^(1/3) ?

Hello,

I discover Maxima and compare it to Sage or Maple.

I feel that Maxima changes about (-1)^(1/3).

My old maxima is 5.13.0 from an Ubuntu box and is fine,
but a more recent maxima in Sage is less nice.
Is there a reason ?

First the (-1)^(1/3)=-1 in the old maxima, and the solve after is right.

(%i2) (-1)^(1/3) ;
(%o2)                                 - 1

(%i4) solve (3*x^3-9*x+10, x) ;
                                       sqrt(3) %i   1
                                     - ---------- - -
              1/3  sqrt(3) %i   1          2        2
(%o4) [x = - 3    (---------- - -) - ----------------,
                       2        2           1/3
                                           3
                   sqrt(3) %i   1
                   ---------- - -
                       2        2    1/3    sqrt(3) %i   1          1/3    1
             x = - -------------- - 3    (- ---------- - -), x = - 3    
- ----]
                         1/3                    2        
2                 1/3
                        3                                                 3

Now I call a more recent maxima built in Sage 4.6.1 at 2011-01-11
This maxima seems to be a 5.22.1 but I'm not sure.
I don't know how Sage works, I only find this library in Sage.
The (-1)^(1/3) remains and the solve result is a little too long.

sage: maxima ('(-1)^(1/3)')
(-1)^(1/3)
sage: maxima ('solve (3*x^3-9*x+10,x)')
[ x=3^(1/3)*(sqrt(3)*%i/2-1/2)/(-1)^(1/3) + 
(-1)^(1/3)*(-sqrt(3)*%i/2-1/2)/3^(1/3),
 x=(-1)^(1/3)*(sqrt(3)*%i/2-1/2)/3^(1/3) + 
3^(1/3)*(-sqrt(3)*%i/2-1/2)/(-1)^(1/3),
 x=3^(1/3)/(-1)^(1/3)+(-1)^(1/3)/3^(1/3)]
 
Is there a reason ? 

F. from France.