Better error messages

You should improve your error messages. They are close to useless as they are now. The only error message Plurk seems to give your is "an unknown error happened". This can mean anything from a server error when saving the message to a locally broken VPN connection or what have you. I am not really sure any "known errors" exist ;-)

How about keeping some state on the client to give more appropriate error messages? You could also set up a service that would send some clues back of what the error might be (for example it could tell if the database is known to be unstable right now). That would improve usabilty vastly and lower frustrations.