UWL - Waiting for update message

Hi,

Can someone explain me what's the reason that UWL shows a 'Waiting for update' info message on top when opening UWL ? Until we press refresh-button the uwl seems to reload every 15 seconds. If we press Refresh button the 'waiting for update' message disappears ...

What does the message mean ? For which update is the system waiting ? Why does it show up every time the UWL is called ?

Regards,

Igor