There's no login/password for EventClient
The important settings is "Allow programs on other systems to control XBMC" this is the one that activate or not EventServer.
You can check that this port is not used by another program by using the command "netstat -ano" that will list all opened port.
Run this command without xbmc started and check that UDP 9777 is not used on 0.0.0.0 then run it with xbmc started and check that the port is now used by Xbmc (check the pid on the last collumn)
You should see a line : UDP 0.0.0.0:9777 *:* 2832
with 2832 is the process id of Xbmc.