I've just updated to Thematic to 0.9.7.8, but when I exported it to the themes directory and activated the theme, I got an error on the index and on the Thematic options page in the admin. Both are sort of the same:
Warning: Invalid argument supplied for foreach() in ... \wp-content\themes\thematic\library\extensions\content-extensions.php on line 443
The admin page gives the same error, just on a different place. The culprit is the $options array, even though it's set as a global variable in the function where it's used.
I've been using Thematic for almost a year now and the old ones never gave me any problems. Same setup.