Do you have any rockettheme plugins installed? There is one of those that causes problems if it was the earlier release (I cannot remember which one).
If you want me to take a look Please PM me an admin account but include a link to this thread so I can easilly find it. However, if you do have any rockettheme plugins installed disable them and see if you can then view the template control panel as you shoulc. When you isolate the plugin then download the updated version from the rt website. If this is what I have suggested they are aware it was a problem and quickly fixed it.
