Ack! If you use 'chmod 777', please only do it temporarily to see if permissions are part of your problem. This opens up a whole can of worms and security problems for your application if any other process owned by any other user can just go in and make changes to files and directories on a whim.

If doing this fixes your problem, please try to find out why this fixed your problem and adjust your permissions or methods so that things continue to be secure. You should never have files or directories with permissions set read-write-execute across the board.