If I had to guess, it will probably go away on it's own. If it doesn't, it's likely something with your home network or ISP. There's no reason I can imagine that it would matter which lounge you're in, but it does matter who the lounge host is. Since D2 has run with the same lounge host for much (all?) of the last several months, and no one else has had consistent problems there that doesn't have problems everywhere, I doubt the lounge host is the problem. That's why I would guess that it has something to with your end.
Of course, all of that is wild speculation
But I do know a bit about this stuff, and that's my best guess. If the problem persists, go through the standard list. Reboot everything (PS3, routers, cable modems, etc.). Clear your cache. Check cables/wiring inside and outside for obvious issues. If using Wifi for your PS3, try alternate router antenna locations/positions. If none of that works, call the ISP.
Edit: And make sure no one else in your house (or your neighbor stealing your Wifi) is streaming movies at the time.