I'm using kde-4.11.1, but this problem happened since 4.11.0. Version 4.10.* didn't have this problem.

Problem #1
When I check the to-do (click on the checkmark).
Since 4.11.0: this to-do will be completed and finished.
Before 4.11.0: this to-do will be "pushed" to the next occurence date.
Is this an error? If not, how can I have the old behaviour back?

Problem #2 (I found this problem when I tried to recreate the to-dos mentioned in problem #1)
How can I make a new to-do that occure every 1st day of the month?
If I remembered correctly, this was not difficult many kde versions back. But since 4.11.0, I can not choose "1 monthly" and "1st day of the month".
For example, today it's sep-14, I can only choose between: "the 14th", "the 17th to last day", "the 2nd Saturday" and "the 3rd to last Saturday"
So I can only create the to-do I want on the 1st day of the month

Edit:
By the way, newly created to-dos are working fine. Problem #1 is only for old to-dos, I have created those to-dos many years ago.