I have recently had problems with CD burning, in the main, multisession burning. The local authorised repairers had my imac for a total of 8 working days to try to find the problem, in the end with advice from Apple they said I was using the wrong brand of disk. However I have noticed that when I have saved a file to documents to burn sometimes this document is in lighter print in the documents table when using Utilities>burn. It then does not burn successfully. Why is this ?. Thanks.