Do you have the Nook HD or the Nook Tablet?
This is what MIGHT work for HD (low chance).
When on the main screen slide your finger down from where the time etc. are listed at the top right.
You'll get a Menu.
Choose Home Settings.
On Home Settings page check the four types. and below change how many subscriptions to keep to more than just 1.
This is what might work for Nook Tablet (again low chance).
Do a restart.
Power Off: Press and hold power button for 20 seconds.
Power On: Press and hold power button for 4 seconds.