Tried the latest kernel Linux ft-desktop 4.4.0-040400rc6-generic #201512202030 SMP Mon Dec 21 01:32:09 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux and it made no difference.
Then started to go back and see which is the last kernel that always boots reliable, and that one seems to be
Linux ft-desktop 3.18.25-031825-generic #201512152250 SMP Wed Dec 16 03:52:48 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
around 30 succesful boots now, will leave it in reboot loop until tomorrow.
Tried the latest kernel Linux ft-desktop 4.4.0-040400rc6 -generic #201512202030 SMP Mon Dec 21 01:32:09 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux and it made no difference.
Then started to go back and see which is the last kernel that always boots reliable, and that one seems to be
Linux ft-desktop 3.18.25- 031825- generic #201512152250 SMP Wed Dec 16 03:52:48 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
around 30 succesful boots now, will leave it in reboot loop until tomorrow.