Cannot Use server on any minecraft 1.0+

[HDmac]

I keep getting a "The server responded with an invalid server key" when ever I try and connect. I have tried connecting with Minecraft 1.0, 1.1 and 1.2.3, they all get the same error. Anyone know whats wrong?
Console displays this:

Starting Authenticator...
Starting server...
ServerListenThread
Starting InputThread...
ServerTickThread
Initialization done, server running now.
Client "192.168.1.13" connected!
New ClientHandle created at 01F45A80
Creating a new cSocketThread (currently have 0)
Client "My IP Here (edited)" connected!
New ClientHandle created at 02F0C570
Deleting client ""
ClientHandle at 01F45A80 destroyed
Deleting client ""
ClientHandle at 02F0C570 destroyed
Client "192.168.1.13" connected!
New ClientHandle created at 01F45A80
HANDSHAKE (My ID);192.168.1.13:25565
User "HDmac;192.168.1.13:25565" was sent a handshake
Deleting client "(My ID);192.168.1.13:25565"
ClientHandle at 01F45A80 destroyed
Saving all chunks...


As you can see, I tried connecting a few times with 2 different accounts. (took the liberty of editing personal info out)

I have tried on Windows Vista as well as Windows 7
help?