I broken the automatic update mechanism in 1.8.1. It's fixed in 1.8.3.

If you are on 1.8.1 or 1.8.2 and want more automatic updates, you can download 1.8.3 manually

After downloading 1.8.3, automatic updates should start to work again. If you happen to still be on 1.8.0 you shouldn't have to do anything.

Sorry for the inconvenience. PieFed support is coming soon. If you're interested, I encourage you to opt back into automatic updates.