nice! Glad that helped!
To make the 3.4 your default kernel you should reboot and see in GRUB the
order in the list. It will be something like this:
kernel bla bla
Advanced options
kernel bla bla or whatever (I don't remember)
You will select "Advanced options" and then you will find the list of all the
kernelzz. You need to remember the position of the libre 3.4 and have to
consider that the list is numbered starting by 0 (0,1,2,3 etc)
So if your libre 3.4 is say the fifth on the list you remember the number 4.
Boot and edit /etc/default/grub
The very first entry is GRUB_DEFAULT=0
You want to make it into -> GRUB_DEFAULT="1>4"
You can also set GRUB_TIMEOUT to 0 if you want grub not to appear at all on
boot and save yourself 5 seconds of time X_X
cheers!