Hey Max! Good to see ya!

Update to 3278 first with this ISO image n20081119s.149_b3278.dss-bas.generic.iso

Then update to with the zip file (there is no ISO because of the new way we format the USB DOM) atlanta_3518.oe.i.zip

Save your settings in Main. > Misc. and take all 4 options that way you can restore them later.