If this is your server you should be able to handle reads and write more effectively than chmod 777. For some reason the phrase "world writable" is setting off alarms in my head.

If this is not your server, keep in mind that they may be using chroot which may change your default directory. Try a test script that prints out cwd and pwd and lists files it can see in "." to get a sense of what your CGI process thinks is the default directory.