This is not really a bug of the Yii-Framework, rather than PHP 5.3.1 and 5.3.2 (its fixed in SVN now)
Some of my web applications thrown some errors while upgrading to Yii 1.1.3 even though i’ve read the upgrade instructions!
This is because CFileHelper::getMimeType have now a new behavior which passes the 2nd parameter of the finfo() function implicit if not set! PHP Doc says its fine to do so, but if this param is set to NULL in PHP versions 5.3.1 and 5.3.2 it results into an error because it tries to load the db at location ‘’.
It would be great to add this behavior to the upgrade instructions.