I am not sure if you tried this or not, but I would try to installthe package
again as 'sudo' or the 'root' user on your system.
I don't know if you have admin rights as your normal user,so I'm only taking a
guess here. Also, the .bin filejdk-6u18-linux- x64.bin needs to be made
executable if I'm not mistaken,and since "root" is the owner of that file, you
need to be root(or use "sudo") to run the chmod command below.

if you are inside the directory wherejdk-6u18-linux- x64.bin exists, then you
issue the commandsudo chmod +x jdk-6u18-linux- x64.bin