it keeps truncating my content in print preview.
When I resize the font the content doesn't flow onto the next page - it just disappears!
I have tried overflow
Following up on what Paul said: (about overflow)
When you only see One Page in FF print preview it is a good indicator that you have overflow:auto/hidden/scroll; on the main wrapping div.
In your printing styles: remove overflow completely from any main wrapping divs or set it to visible.
I ran into that bug just a few days ago with one of my own pages. I did have some floats in the header and I was able to print successfully with them since they were at the top of the page.