Was the attention light on? If so what was happening with the happy and hungry hearts? Were they empty? If they were - they might have needed refilling rather than training.....
have a read of this:
When your tama beeps and the attention light is on (the icon on the bottom of the screen farthest to the right), and it is NOT on because the hungry and/or happy hearts are empty:
1) if the tama is crying or in a bad mood with its back to you -> PRAISE IT
OR
2) if the tama looks like it normally does and doesn't have ALL of its happy and/or hungry hearts gone -> PUNISH IT. This will lower your happy meter by 1 heart quite often - so i always fill up the happy and hungry hearts first, then punish, then check the happy hearts and give a snack or play a game to refill the heart if needed
Note: If the happy/hungry hearts are empty - they will need refilling rather than praising your tama. You can do this by feeding meals (hungry hearts) and snacks or playing games (happy hearts)