ADE only displaying the top-half of each page of my eBook

I am trying to view my purchased eBook (from eBook.com) in ADE. However, in ADE, it only displays the top half of each page. I have tried to change any sizing and viewing options under the 'Reading' menu, but nothing is working. Under that same 'Reading' menu, I can only view my eBook in the ePUB format (in the 'Reading' menu), as all the PDF opions are grey and I am unable to press on any of them. Please help!