If you change the tab height in Ext4. The TabBar does not automatically adjust its size accordingly. Therefore, the tab becomes hidden due to overflow problems. When defining a new Ext.tab.Panel you can override the configuration options for the tabBar that will be created. Here was my solution:
The reason I manually set the height of the components body was because it seems that in Ext4 the configuration for bodyStyle: in a component was removed. This used to be a very handy config option so hopefully it will be put back in. Of course, it may still exist in some other form, but I have no been able to find it. Hope this helps.
height: 50 //sets the default height of the actual tab
height: 65, //sets the height of the tabBar component
// this will set the height of the tabBar body to the height of the tabBar component