Mass Headers:
If you are using the Shrink option in an action because some documents need it and others don't, I have found a work-around for the issue.
In your action sequence, insert the [Add Header & Footer] step TWICE.
The First Time you set the Header & Footer to add a _ as a footer (and make the text appear white so it is invisable)....do NOT select the Shrink option for the first step.
The Second Time you set the Header & Footer to add whatever text you want to appear and select the shrinkage option.
Basically, you are tricking Adobe into thinking there is already a footer in place so it does not centre your text half way down the page.
Example of steps in an Action that I run:
1-Recognize Text using OCR
2-Add Header & Footer (no shrink)
3-Add Header & Footer (shrink)
4-Reduce File Size
5-Save
Hope this helps. :)