Weird, wouldn't have thought would be affected by Windows OS... I'll just demonstrate (via some shoddy illustratration) to show I'm not mad when I say it happens here:
As you can see, I set an ignore with -tu30 and the dialog shows [0].
I managed to open it again just in time, and as you can see it now displays [1] where 29 seconds have passed.
6.14/XP Pro.
Regards,