It's impossible to select whatever I want task. For example tasks: A,B,C,D. I want to mark as done task C. But when I click on C, task A was marked. Next click will mark B, next click C, next click D.
Confirmed. It seems this is the same issue someone else reported at Debian's bug tracker.
Create two tasks, select the second task (it is highlighted now) and then try to mark the
first task as "done" but the second highlighted one will be marked as done.
Thats unexpected and also happens with more than two tasks.