Poster Print Pages do not line up

I need some help.  I am trying to print a large file with poster (tiled) print. 

It is 2x4 (8 pages) on 11x17 paper. 

It prints fine but the problem is when I go to put the pieces together they do not fit. 

For example when I go to put page 1 together with page 2, page 1 is so much longer then page 2 it actually sticks out the bottom and the top of page 2.  Its like page 1's scale was stretched out.  so it is impossible to line up.  If I line up the top of the page, the bottom goes way past where it should line up. if I line up the middle both top and bottom are out.  I hope you get the picture. 

I've tried with a .002 overlap and with a .5 overlap.  same thing. 

I don't know if it has something to do with the margins that are there when you print.  I have to cut the pages then line them up.  Or if you can even get rid of them.  In the print preview there are no margins.  

If you google it everyone says it is so simple, but the pages simple do not match up ever.  It does seem worse with a bigger overlap, but I would imagine a zero overlap won't matter because .002 is already pretty much zero. 

I did notice that increasing the overlap makes the scale larger.  So i am going to try decreasing the scale so the print scale is actually 100% instead of 102%. 

hopefully someone knows how to make these pages lineup other wise this poster print is useless.