You might want to try 664 with a group ownership of the Apache user (not sure what it is on your setup). Most hosting packages block the world writeable (xx6) setting. So by setting the group to the apache user and giving group write access (x6x), you should be ok.
EPC Tutorials... We're here to help!
Offering custom integration services. Contact me here
* Not affiliated with EasyPHPCalendar or NashTech Inc.