So 1.7.2 allows,

 p (-2)*(-2)

yielding '4'.  (Note: 1.6.7 doesn't allow this construct.)

However, for a mathematically equivalent expression,

 p (-2)**2

I get '-4'!?  But if I prod further and wrapping things in parentheses,

 p ((-2)**2)

I once again achieve the expected value of '4'.

Why does an extra set of parenthesis change the sign?

Is this some sort of parsing thing?

 % ruby -v
 ruby 1.7.2 (2002-05-23) [i686-linux]

Surprised and confused,
-- 
Bil