I'm just WAGing here, but check your settings to see the age of threads that you're viewing.

Check your settings under "General Settings." Look for the "Thread Display Options" section. Look for "Default Thread Age Cut Off." When I checked mine just a few minutes ago it was set to only show threads from "Last Day." I changed it to show threads from "Last Week" and bingo, more stuff showed up.

As I said, I'm guessing at what your problem might be. So I reserve the right to be wrong. But it's worth a look either way. I've spent the last thirty minutes twiddling with settings, trying to get it like I want it.

Let us know if you still have a problem.