Affects Version/s: 1.6
Fix Version/s: 1.7
1. Go to contact view (civicrm/contact/view), for the contact with at least one activity registered
2. Click "Activities" tab
3. Click + icon to see the list of activities
The tab bar disappears.
Similar thing happens after defining category for contact - after submitting the category change screen (civicrm/contact/view/tag?action=update) it comes back to Groups tab instead of Tags tab.
... also New Membership does this.