There is one pc (vista os). Two i-Pods, a 64g Touch and an 8g nano. There is one library but I have 2 accounts on i-Tunes store. One U.S. and one U.K. I only get the error message when I am ripping cds. It's not on all cds or even all tracks within a cd. I might get it maybe three or four times on a cd then nother on the next few cds. I am ripping at Apple lossless. My library at the momment stands at around four and a half thousand tracks. About a third through the collection. I also have the 'let i-Tunes organise names, folders' ticked, 'make copies in media folder' ticked and 'sound check' ticked. It's not a major problem, I can't just leave the pc ripping and go do something else.