Problem when alpha fading a loaded movie

1

I know there have been many posts on this, many of them from myself but I seem to have trouble once the situation is slightly different from an already posted situation.

I am trying to slowly fade a loaded movie (fade the container clip) trouble is, I can get it to _alpha = 0; but it jumps, does not fade.

Here are two examples of the code I have been testing
(I gave up on the first one, which is why I tried the second and it’s still not working)

This seems to jump to an alpha of about 20%:

function fadeRMS() {
	clearInterval(fadeRMSInterval);
		if (_root.holder24._alpha >= 0)
		{
			_root.holder24._alpha -= 20;
		}
		else{
			delete this.onEnterFrame;
		}
}
fadeRMSinterval = setInterval(fadeRMS, 60000);

and this jumps directly to zero:

function fadeRMS() {
        _root.holder24._alpha -= 4;
        if (_root.holder24._alpha > 0) {
        _root.holder24._alpha = 0;
        delete this.onEnterFrame;
                        }
        };
fadeRMS = setInterval(fadeRMS, 60000);

Could someone let me know what I am doing wrong? I will continue to test, it may be as simple as a - where there should be a + or < where there should >.
That just gets very time consuming.

Also, could you please tell me if one of these ways is better than the other, and why?