I erased my ID and can't get a new one

After authorising I failed to download am .acsm book, there appeared ALREADY fulfilled by another user. So, I erased my ID (thinking I might do it again), but i doesn't work as I already registered from my e-mail. Anyway I am not sure where the problem is and if a new ID will help downloading or not. I've been trying for hours already but no luck. Please help.