I've just downloaded and installed the new Version pkg_cobalt.v.7.8747.zip
My Joomla Version is 2.5.6
The installation message says successfull installed but at the first click on cobalt_7 in the menue causes a database error in case of not installed databases.
Then I've checked the database and all tables for Cobalt 7 wasn't installed.
Now I've installed them by hand and now Cobald 7 works.