background band printWhenExpression timing

In my background band, I have a number of black text fields that go along the edges of the document. The idea is that for a large manual, when you look at the edge, you can easily get to the chapter you want.

I have 3 areas (top, middle, bottom) where these text fields can go. When I switch from chapter 1 to chapter 2 (I have a chapter group created), I want the top text field to turn off and the middle to turn on.

My problem is that the background band's "print when expression" is evaluated BEFORE the page is rendered. My counter variable that is used to trigger the switch from top to middle never gets incremented until the chapterHeader band is evaluated AFTER the background band.

This results in the contents of a new chapter being printed on the page, but the black text field being in the wrong location.

Is there any way I can have the background band evaluate at the end?

Thanks in advance,
Andrew