hello. i used to have the exact same problem as you, vurt, and on reading this thread decided to investigate and then make a mobileread account to share my findings:
i was able to reactivate the pageturn buttons on the voyage by setting the fsrkeypadEnable and fsrkeypadPrevEnable properties on com.lab126.deviced (back) to 1 after launching koreader with the no framework option.
Code:
# lipc-set-prop com.lab126.deviced fsrkeypadPrevEnable 1
Code:
# lipc-set-prop com.lab126.deviced fsrkeypadEnable 1