Some sheets printing darker than others

I have a new file that I created in which I placed 4 sheets around my drawings. All of the symbology is the same for each sheets drawings, however when I go to print the 3rd TYPSRD02.dgnand 4th sheet come out much darker.

I don't understand. I have no references, there aren't any duplicates...this is whether I use print organizer or fence print.

I used the FDOTPDF plot driver. Attached is the file...can anyone enlighten me as to why sheet 3 and 4 turn out much darker?