hi all I need a little help. I tried today to record on my MZ-N505 a new album. This album has 20 songs . After the software finished tranfering all songs, I discovered that only few are playable ... (about 10 good songs and 10 corrupted songs). for example, I press play on track number 12 and the md is stuck till I choose another track.... I press play on track number 13 and it's OK ... SO .... I erased the disc and tried to record the same disc again . Now I can hear track number 12 but track number 13 is corrupted ... BTW, it was a brand new MD... anyway, I replaced the disc with another brand new disc and it has the same problem ... I have the latest MD software (web installer) and my windows has all updates. I thought maybe I need to clean the lenses but THERE ARE NO PROBLEM WITH PLAYING OTHER DISCS !!! what can it be ?