Amin,
Did you turn off the "recent discussions" column on the right side of the page or did I somehow change something that turned it off? That's the best navigation tool I've found for checking the site quickly and seeing if there's an ongoing discussion that's been updated and, at the moment, its gone. Was it something I did or something you're doing? If its something you're doing and if you're thinking about disabling that feature, here's a request for keeping it - I find it highly useful!
-Ray