I don't have a server with that exact php version handy for testing, but it's certainly not normal. Mahara is probably throwing a ConfigSanityException because it has detected that your server is somehow configured in such a way that it can't run Mahara.
Usually it would display a more useful error message.
I'm not sure what to suggest at the moment, except that it's worth having a look through the dependencies listed here, and just making sure they're all installed on your server:
http://wiki.mahara.org/System_Administrator's_Guide/Requirements
You should also have a look in the webserver log to see if there's any more information about the error in there (probably not, unfortunately).
]]>The following error occurs when attempting to install Mahara 1.2.5: Fatal error: Trying to clone an uncloneable object of class ConfigSanityException in /pub/home/chertkov/fudzimama/lib/errors.php on line 457.
PHP Version 5.2.5
Thanks in advance,
Sveta
]]>