Changes in T3 Template not being saved anymore... :(

Hi,

All of a sudden, I cannot save any of the changes I make to my T3 template in Template Manager. I cannot close the template manager either, I actually need to log out and log in again to the admin back-end.

The rest of Joomla is working fine. My site is up and working fine. The issue only seems to do with the T3 template.

What can I do? Help!

Hector