Thanks, holding back 'linux-dtb-current-sunxi64' works for me too.
Performing a diff on the dts with
dtc -I dtb -O dts -o /tmp/sopine.dts /boot/dtb/allwinner/sun50i-a64-sopine-baseboard.dtb
Finds, apart from some odd white space changes (< x > becomes <x> and <x> becomes < x >) the following differences in the dts:
I have not been able to confirm whether the removing the dts changes is enough to make it boot but looking at the contents of the package 'dpkg -L linux-dtb-current-sunxi64' it looks like it could be