I also did two installs of rc6 on a virtual machine and updated them to rc7 they worked fine.
A few minutes ago i just finished updated my server (using rc5) to rc7 and there were no problems.
It looks like this is the first stable release of ispcp. Great job sci2tech and the rest of the dev team

.
Actually there is one bug

. On "http://admin.domain.tld/client/sql_manage.php" when trying to click on "phpMyAdmin" it opens a new window but it says "Cannot log in to the MySQL server". If i try to login manually it works :-?.
It seems it's not from ispcp update, i've probably done something wrong because it works fine on the virtual machine... could be from config.inc.php