Color Matrix Problem

I have a movieClip(contentMC) that contains numerous movieClips for my site. I have set the color matrix of contentMC to be black & white.

This works fine by itself but once I start duplicating and populating movieClips inside 'contentMC' the color matrix settings are lost.

var nocolour:Array = [0.3086, 0.6094, 0.082, 0, 0, 0.3086, 0.6094, 0.082, 0, 0, 0.3086, 0.6094, 0.082, 0, 0, 0, 0, 0, 1, 0];
var colour:Array = [1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0];
var greyscale:ColorMatrixFilter = new ColorMatrixFilter(nocolour);
var fullcolour:ColorMatrixFilter = new ColorMatrixFilter(colour);
contentMC.filters = [greyscale];

I've even tried to populate the content and THEN turn it B/W thinking that it would be better to convert the contentMC to BW after it was done building itself. This didn't work either.

So I started to comment out code until the color matrix settings would stick and this line of code is the killer but unfortunately is essential to rendering the site.

contentSC.samplesMC.sample._y = contentSC.samplesMC.sample._y+621;

(this line offsets a duplicated movieClip)

Any ideas? Need more info?