Same problem.

Trying to delete from the project view. (click right or also on dropping)
The time entry remains on screen.

trying to close and restart klok

the entries are always here.

but this time when deleting from project view the entry is removed !!!
But after switching view… the entries are here !
trying to delete them agin…. stay on screen…. etc….

Version : 2.0.7
For information my entries has a duration entry of 0.