Pretty exciting stuff. Definitely thread worthy.
It's called a netsplit. You're not all on exactly the same server - if one goes down everyone on that one 'quits'. To them it looks like you're the one that's gone. Common happening in IRC.
I blame the liberal media.
Standard stuff, no cause for alarm. As Lily said it is a netsplit. Everyone is connected to different servers and those servers connected to each other to make up the IRC network. Should 1 of these servers go you get the affect of everyone "leaving".
It is possible to change to a different server to join evgeryone else but you would have to look how to do it www.darkmyst.org