The server that hosts a lot of the older comics (such as BT and Shifters) has croaked. I don't know when it'll be back up. You can still see CF because it's on a different server than BT. BT will be posted on the donator site as always, and I'll be posting them on the Keenshift forums later. If you read Shifters, ShadowsMyst will be posting updates (not sure if that means comics) on the KeenShift forums as well.
I don't know if CF will be able to update with Boardy being down, so if it doesn't, I'll be posting it on the keenshift forums as well.