Gary Burmore - 2007-02-05

From your source code:

echo "Could not create cookie file. Please make sure your web server user
                can write to this folder or alternatively, make an empty file called
                '.paypal.cookies' and chmod it 777

Nonononono!

777 = read/write/execute for everyone!  A very bad idea!.   Make it 640 or 644 or at most 664, but don't add execute permssion and certainly don't set it so other (world) can write or execute!