Incessant buffering

For the last few days I've been suffering from incessant buffering. It happens on WiFi, 3G, and hardwired LAN. It happens if I'm accessing the server over a local IP or via a port forwarded through a VPN service. It happens with Windows Firewall on or off on the server. I'm at my wits end.

I've restarted the computer, modem, router, the attached storage housing my library, *everything*.

Any thoughts?