problems with id

I downloaded an ebook from a Library and I was able to read it in Adobe Digital Edtitions, but now I can't. There is a conflict with the ID. Error: License is for another user account. Maybe when I downloaded it, Adobe Digital was activated with no ID. and after I changed the ID. I have tried to download acsm again from library but it returns error "Cannot download LIC ALREADY FULLFILLED BY OTHER USER". How can I solve this problem?