When I click on an xref, the xref window flickers. While it does, autocad locks up for 3 seconds or so. This also happens when I click on a block. The "Change Path" button flickers a lot more than the other buttons in the xref window, though I'm not sure if that's relevant.
I don't get this problem after a fresh reboot. I've got 16GB of ram, though, so it's not like I'm starved for resources. Any theories?