Icons in ion-tab not vertically aligned

Hi all, when creating an ion-tab and adding ionicons within, I’ve noticed since 1.0.0-beta.5 the icons are not displayed in their vertical centre. Is there a class I am missing? If I use beta.4 the icons are vertically aligned in the middle.

The screenshot is after me swapping to http://code.ionicframework.com/1.0.0-beta.4/css/ionic.min.css however when using ion-ios-checkmark as an icon, it positions itself at the top. I know of ways to hack around this, but surely this is undesired. I must be doing something wrong.