I apologize that I didn't open a new topic...
Thank you so much for your reply and for the explanations, Steve!
Unfortunately, I still can't figure out why my OBi's Google Chat session is getting disconnected.
I was using the Simonics gateway but I unlinked it from my Google account - the problem persists.
As my OBi has a static IP, there shouldn't be any DHCP lease problem.
About my ISP - I have no idea ("regular" VoIP services are blocked in my country but Google Voice is working fine).
Any other ideas apart from rebooting?
(If all else fails, I should maybe use a timer switch, as suggested in
this thread...)