Just installed a fresh copy of 2.2.0-pl2, started building out a few templates.
I have a Homepage template (the original BaseTemplate), and a Subpage template. I created a Home document, left the Homepage template selected and it works as expected. I created a Subpage document, applied the Subpage template, pressed 'OK' on the warning, the page refreshed, and the homepage template is still selected.
Repeating the process, I noted a few errors in the console.
In Chrome 16.0.912.63, after pressing the 'OK' button I receive:
Uncaught TypeError: Cannot set property 'leaf' of undefined index.php:49
In Firefox 8.0.1:
In Firefox, if I stop the page immediately after the errors appear, I can then press the 'Save' button and the changes are successful.
I'm receiving similar errors in the console when using out drop-down boxes, but the changes are saved successfully.