Three of the four Activation Key sub-tabs are missing the header when clicked.

Steps to Reproduce:
1. Navigate to Systems > Activation Keys
2. Select a key.
3. Click any of the perl tabs: Child Channels, Groups, Activated Systems.

Actual results:

Header disappears.



Expected results:



Additional info:

The Edit.do page initially presented after selecting a key appears fine, it's only a problem on the remaining Perl items.