The mysterious filter issue

I have a movie i’ve been working on with a double layered infinite menu. The top menu is revealed through a mask, and the bottom menu is contained within a movieclip that has an “adjust color” filter on it, it is set to -100 saturation so that it is black and white.

For some reason, when clicking on items in the infinite menu, it decides not to use this filter any more. Any ideas would definately make my day.