I have this problem too. I get an error saying that session-at-once and disc-at-once are not supported oj my CD drive. But they work OK with Nero, which is the only other burner I've found which allows gapless writing. I'd like an explanation as it's the only thing which stops me using this as my 'standard' burner. My drive is a Sony DVD/CD RW DW-D22A.