Sandaz, if you have low stocking and are doing regular water changes then yes, the tank could still be cycling. Because a reading of 1 is toxic to fish I believe that the ammonia is being held 'locked up' by the stability. Your best bet is to continue with small daily water changes while using Prime. If the tank is cycling you should see the ammonia drop and nitrite rise etc until the cycle is completed.
Frankenfish, If you are still getting ammonia appearing you will need to look for the cause. Could be any of the following - overstocking, filter not working properly or being cleaned out wrongly, overfeeding, water changes insufficient, plants decaying, dead fish. A tank once cycled should not show ammonia if the maintenance and care schedule is is right. If you have the ammonia sorted then well done