Thanks for the reply DonTomme!
Indeed, i get "CONFIG_MMC_UNSAFE_RESUME=y", which makes me wonder, if there is more than one switch, you need to change in the kernel.
Seems like we are not the only ones with that problem, i stumbled over this ubuntu bug report
https://bugs.launchpad.net/ubuntu/+s...ls/+bug/342096
Sadly the cable option is no way to go for me, cause then i could use a normal tablet.
Having a wall mounted display, that you can put anywhere, without having to worry about the power consumption for a long period of time is what makes the kobo so appealing to me.