I don't have the answer for you but I double checked mine and the same thing.. one arm preacher curl on stability ball is on workcard for disc #1 and N/A for disc #7.
SNM: Can you help me too - when I mark my workout complete, the minutes, met value and calories are not there.. when I add them and go back, they are gone. Please see my question and response in the Workout Manager Support.
Thanks
As soon as we have an answer we will let you know. This is something we're aware of, but haven't gotten to yet.