Matte line is cropped - easy fix?

Hello,

I am a student and pretty new to After Effects. I created a matte around an object I am keying but for some reason the top inside part of the matte seems to be cropped of the ability to make changes.

Here is a link to a screen shot to better illustrate my problem.
http://www.hotlinkfiles.com/files/2745498_8yjjx/matteproblem.tiff]matteprob...

I've tried adjusting the matte position and size but the top area remains constant. It seems like I'm missing some silly little thing here, any help would be greatly appreciated.

Thanks,
Brad

Hi Brad,

Your mask is extending beyond the edge of your adjustment layer. The adjustment layer
is basically a comp sized solid.

With the adjustment layer selected go to Layer>solid settings. you can
increase the size of the solid here.

Rather than animating the adjustment layer you might have better luck animating the mask.
If you twirl open the mask properties you can see the mask path property. This is where
you can animate the shape and position of the mask.

-Andy