Funny, it must be contagious! After I looked into the theme.php file in wp-admin, I changed the wp_redirect function name just as a test, and started to get the same error that you describe - I absolutely was not getting this error before I edited the file. To my amazement, after reverting the file to its original, the error still appears!
Well I gave up on trying to figure it out because I've settled down on a theme anyways, just wanted to see.
The $template variable is used frequently. I am not sure where it starts or what its exact powers are though, because it is used in different ways on different occasions.
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