Okay, let's drop back a few steps and get our story straight:
1. What version of Word are you using?
2. What is your operating system?
3. What does the main document you are inserting consist of? How many
pages? Just text?
4. What does the document consist of that you want to insert into the main
document? Just text? You mentioned a form. Is it something you scanned in
as am image? Is it created with formfields?
5. Did you create the extra page at the end of the main document by placing
your mouse at the end and pressing CTRL+ENTER? At that point, did you click
"Insert", "File", browse to your other document and select it? Exactly what
do you mean by, "The only thing that inserts is the text, it leaves the rest
of the form behind".
Hopefully this will assist in providing an answer.