(I realize this may be a bit difficult for you trying to create the bug, so just putting it here.)
As explained in the title. If I leave the program running through the night, then (in addition to the ConcurrencyModificationException I reported earlier), viewing the task list will only show the "pending tasks" in the previous day and not the current.
If I keep opening it for a whole week (or maybe 2 weeks I don't remember), then exit and reopen the program, it will never be copied to the current day.
Thanks for the bug report. Just to be sure, can you verify that you have the Move unfinished tasks option checked in the System > Settings?