setting _alpha is futile: integers are so yesterday's thing

It was the day that the Flash Player gained consciousness. The web's transparency will never be the same...

Go ahead and paste this code into a new fla and watch the traced values

this.createEmptyMovieClip('mc', 1);
for(i=0;i<101;i++){ 
 trace('Setting _alpha to > \t' + i);
 mc._alpha = i; 
 trace('Alpha value is > \t\t' +mc._alpha);
}

I mean, wtf!
I think the answer lies in this post from tha playa who makes the Flash Playa but man do I miss those brain cells I burned last evening on this quirk :(