Latest update and removal of speed patch together with restore of Nokia kernel solved my rebooting issues. After all I think that it was the speed patch that caused problems in the first place, not the CSSU. I did install speed patch day earlier than CSSU. And phone kept rebooting even with the latest update, but right after removal of speed patch and restore of nokia kernel no more reboots.

Many thanks to hard working CSSU Team.

BR,
nibbe