When you run your yii app on shared server in which the PHP SAFE MODE is ON, you might facing the SAFE MODE RESTRICTION.. UNABLE TO COPY BLA BLA BLA..
I have found this extension ‘safemodeassetmanager’, and it’s really useful for me to solve that problem. Thanks to the author.
Here is the extension link: http://www.yiiframework.com/extension/safemodeassetmanager