| | Seen that too
I have also seen a similar problem.
If you have a filter set in your tasks, and then change the task due date to be later in the week, when you go back to the tasks screen, it says "No Tasks".
However if you do anything like click the scroll wheel and select New and then immediately hit the ESC button to go back, all of the tasks appear again.
Definitely looks like a bug in the OS.