[namder]

John, could it be that after typing something in the 'search all fields' box, you are closing the filter window without clearing it? Because if you do that, the filter will remain active even though it's no longer visible.
If you no longer want the filter active, you need to press the circled x at the right of the filter window before closing it.

Thanks for the suggestion but that makes no difference to the problem I am experiencing.

John