[Observium] Wrong ports counter / reset counter

Hi,

I've some weird behaviour with observium. Since some time the ports counter on the frontpage is displaying wrong values. Eg. It's showing that there are 264 ports down, but when I click the link, there are only 23 ports down. Also when I add up the up, down, ignored and disabled ports, the total number (13326) is less than the number observium shows under 'total' (14991)

Does anyone have an idea where to look? Or is there a way to reset the counters?

Thanks! Onno.