PDF files partially printing out black

Hello,

For the past two years there has been a serious problem where some customers can not properly print out my PDF documents.
The problem is that this does not apply to all customers. Only some of them.

What happens is that in the viewer the PDF files show exactly the way they are intended but then when they are printed the middle of the document has a big black box covering the data that is on on the page.
It's not the same as where lines get covered in black(so not an encoding or font issue).
Even a part that has no text is being covered by this black rectangle.

I am NOT using an overlay in the PDF file.
However when i advise customers to print out the file as an image (by setting this in the advanced settings) the document gets printed just fine.
A select few even claim that not even printing as an image works for them though i suspect that they make that claim because they don't feel like changing the advanced settings.(out of hundreds that experience this issue there are only 3 of them that claim this work around doesn't work.)

Those same customers get to print PDF files offered by other companies no problem.

Either way it does not come across as professional when i offer customers this work around as a solution.
They ALL feel like i should remake the PDF files. which has been done already. several times.
using different software even.
Is there anyone experiencing the same issue? is there a solution for this?
I can not keep telling my customers to use this workaround as they are getting frustrated over this.
This is also not a consistent problem.
I have advised customers to update all drivers and adobe acrobat software yet it still does not seem to resolve the issue.

to sum up.

- PDF file shows to be perfect in the previewer.
- When printing the file it becomes blacked out partially.
- I am NOT using an overlay.
- Files print out correctly when printing as an image.
- Customers that experience this problem only have this with my files.

I cannot attach said documents as they contain sensitive information.

Description of File:

-My companies details - left upper corner (prints correct)
-Customers details - right below my companies details (prints correct)
-My companies Logo - upper right corner (prints correctly and in color)

-More customers details - below logo(prints correctly)

-Box spanning almost the entire width of the page containing document specific information {box created in as400 application using BOX(param param param param param) command} (this is where the black rectangle starts)

- Open space where there is nothing added (black rectangle uninterrupted)
-another box with headers for the tabel below this spanning same width as previous two items (black rectangle still uninterrupted)

- rectangle containing data in table format spanning allmost all the way down the page {created in as400 application using LINE(param param ) command} (black rectangle still uninterrupted)
-two more  boxes each spanning a third of the width separated by a third of white space {made in as400 using the BOX command) (This part is still inside the black rectangle. this is where the black rectangle stops.)
-White space between table and footer (prints correctly)
-Footer with metadata (spanning almost the entire width of the dowument) (a third black rectangle + a third that prints out as it should + a third black rectangle)

I have gone as far as picking this File up with a Java program to rewrite it yet the problem persists.
Every customer experiencing this problem is using Adobe Acrobat Reader.