Cracked Server in LAN

He there,

I've downloaded the Minecraft stuff from here:
http://www.mpgh.net/forum/335-minecr...mpghcraft.html
And I downloaded the server stuff from here (before I changed the 'host' file):
htt p://www.minecraft.net/download.jsp

Now a mate and I wanted to play it in LAN. But everytime I create a normal server and try to connect with the cracked Minecraft.exe the program crashes. What am I doing wrong? Could somebody help me fix the issue?

Thanks!
Thomas