Downloadfail

I borrowed an e-book in an online library and downloaded it at the PC. Now i want to read it at my e-book-reader but i can't send the e-book from PC to reader. It says "CE_COPY_NOT_ALLOWED". I also cant't download it via the e-book-reader browser. it says "E_LIC_ALREADY_FULFILLED_BY_ANOTHER_USER" but the PC and the e-book-reader are both authorized by the same Adobe ID.  Please help