Smile root samsung s6310n problem

Hi all
Newbie here. Trying to root my sons phone.
I have followed the guide for rooting using rootmaster.
The program says it was a success.
However...when i then try yo install root browser or any other program i get the error "OUT OF SPACE could not install. free up some space and try again"
Frustrating because that's the whole point in rooting in the first place.
My phone has 1.1gb system memory free so why cant I install anything else?
I have followed the guide on here and have root explorer installed but cannot get any further.
Any help please??