You do know the easiest way to do this is:-
1/ Disable your 'show pre-release beta' option thingy
2/ Shift+right click on the game and select verify installation
3/ Impulse will tell you it isn't right and ask you to updat.
4/ update elemental (about 20 meg download)
5/ recheck 'show pre-release' thingy
6/ update elemental (about 30 megs)