Icons not working in ionTab

Hi everyone,
I'm playing with Ionic v2 and just noticed that some icons does not work as expected in ionTab components.
Here is my code:

<ion-tabs>
  <ion-tab [root]="tab1Root" tabTitle="Tweets" tabIcon="water"></ion-tab>
  <ion-tab [root]="tab2Root" tabTitle="Angular" tabIcon="angular"></ion-tab>
  <ion-tab [root]="tab3Root" tabTitle="React" tabIcon="nodejs"></ion-tab>
</ion-tabs>

The first icon called 'water' is well displayed on the screen (I'm running my app in chrome) but none of the others...
What I'm doing wrong?
Thanx