I posted a similar inquiry in a different thread in the Themes forum, but it hasn't gotten any attention there at all. So I'm trying it here..
Trying to activate a new theme will result in an infinite loop when you visit the website after changing the config.php. You can't change it back to the old theme and have the site working normally again.
The only fix I've found is to completely wipe the site and start over again with a fresh install. Then of course, we're back at square one when trying to switch to a new theme.
BTW... obligatory info:
Linux CentOS on a dedicated server
SS 2.4 beta / 2.3.6 ( I tried both versions )