Nero cd burning problems

i am using the acer 6406eu external cd burner. I had nero version 6 but it ws not compatible wiht my burner so i downgraded to nero 5. I can now add files to my audio cd and do everything but burn. The system recognizes the burner and the cd type and procedes to do the burn simulation then I keep getting the error " invalid block address" please help, i need to burn this cd asap. thanks.