time machine very slow 400gb over 14,000 days!!!

ok This is so stupid i can't believe this is still a problem. So updated my mac to 10.7.5. and i can't seem to back up with time machine anymore. I am backin up thru wifi to a seagte go flex 3tb external. I have read about the spotlight issue but cant seem to disable it. I have tried useing two different methods in terminal. Anyone have any luck with this? or can you tell me if the follwing terminal steps are correct.

to disable spotlight

use terminal

type : sudo nano /etc/hostconfig

move thru menu to SPOTLIGHT=-YES- change to SPOTLIGHT=-NO-

save by typing control o then exit control X

Then disable indexing

sudo mdutil -a -i off

restart and spotlight should be off. However mine loads everytime.

so frustrated below is a screen shot of the stupid time machine screen.