I don't get the message overrun.
The procedure I used is:
1) Burn the Samplerbox Image to a SD-card
2) Overwrite everything in the boot partition with the boot-partition of the latest version of Jessie Lite:
a) the boot partition is the partition you can read when you insert the SD-card in a windows PC
b) you can unzip the Jessie Lite with 7-Zip
3) Use the cmdline and config.txt as I placed here above
4) Boot your pi
5) remount the filesystems in read/write ( mount -o remount,rw / ) and run apt-get update and apt-get upgrade (and reboot the pi)
Succes!
Kees