You have to put the option on for sticky ik handels. That rig was done in maya 4.5=).
To get the Iks to work right you select the ik handel, hit control A> find Ik handel attributes> find stickness> make sure its has sticky selected.
That should do it.
Kurt
I am enough of an artist to draw freely upon my imagination, knowledge is limited, imagination encircles the world. (Albert Einstein)
https://www.artstation.com/kurtb