Hi caroa2,
Thanks for informing us about the issue you are having syncing your iPod nano with nikeplus.com. The resources below will help troubleshoot this issue. The first step is to identify which model of the iPod nano you are using. Then, make sure you have the latest version of iTunes installed on your computer. Finally, contact Nike for support for syncing with their service.
Identify your iPod model
Nike + iPod
Sync
When your run is finished, your iPod touch or iPhone wirelessly sends your workout data to nikeplus.com from wherever you are on the road. With iPod nano, your data is sent to nikeplus.com when you connect it to your Mac or PC. Go there to see all your completed runs and share motivation with runners across the world. Learn more about sync
Nike + iPod - Stay in Sync
If you walk or run with iPod nano, workout data is sent to nikeplus.com when you connect it to your Mac or PC.
Nikeplus.com keeps stats on your every step. Its intuitive interface and great graphics make it easy to see and remember each run and each workout. It helps you track your progress, analyse your performance, break your last record and see how much further you want to go. And you can check your speed, distance and calories burned — by run, by week or by month.
Nike + iPod is compatible with iPod nano (3rd generation or later), iPod touch (2nd generation or later), iPhone 3GS, iPhone 4, iPhone 4s, iPhone 5, iPhone 5c and iPhone 5s. Not compatible with iPhone 6 and iPhone 6 Plus.
The link below will get you in touch with Nike support. Choose the link for the model iPod that you have (Generation 7, Generation 6, or Generation 1-5.)
How Do I Set Up Nike+ iPod on the iPod Nano
Note: Your iPod nano should be set up in iTunes and running the current software version before you get started. If you need help setting up in iTunes or installing your iPod's software, visit Apple's iPod support page.
Enjoy your day!