On Tue, 16 Apr 1996, Lizsue wrote:

Suppose he reaches 80, turns into a young woman and stays that way for 500 
years.  What happens when she is 580 and turns male again?

Yikes, mail overload.

Anyway, this isn't quite right, though...remember volume 33 of the Ranma 
manga, anyone?  With the magic mushrooms Ryouga found?  Both Ryouga and 
Ranma ate the mushrooms in NON-CURSED form, reducing them to about age 5, 
but when doused with cold water, Ranma turned into a cute little 5-year 
old girl, while Ryouga turned into a really tiny little black pig. :)

Given this evidence, I'd assume that the cursed form ages normally from 
whatever age it starts at.  So if you GOT the curse at 80, you'd have a 
yong cursed form, I'd presume...but Ranma, having gotten the curse at the 
same age as the cursed body, should be roughly the same age in both.

Of course, this is all conjecture given one particular manga storyline. :)