I have some pdf files on my computer. On the computer, they have content. When I upload them onto itunes, the cover is white as if it's blank. When I click on the pdf file in itunes to open it, it has content. When I sync it with my ipad 2, the cover is blank but there is no content. Out of 200 pages, maybe one page transfers over. The rest are just white blanks. I transfered about 150 pdf files and this happened to maybe 25 of them. How do I fix this. I deleted the files and reuploaded and resynced them but that didnt work.