[Help-gnu-radius] problem on authentication

[ng wai wing]

I have added a person called 'Nick' with plain password 'abc'.
However, when i try to run radauth, it shows the followings:

address@hidden raddb]# radauth -v -slocalhost:footbar Nick
Password: 
server 127.0.0.1:1645
send code 1 (RT_AUTHENTICATION_REQUEST)
      send: User-Name = Nick
      send: Password = abc
      send: NAS-Port-Id = 0
radtest: warning: Received invalid reply digest from server
recv code 3 (RT_AUTHENTICATION_REJECT)
      recv: Reply-Message = \015\012Access denied\015\012
expect 2
got    3
FAIL

Then, what is the problem?
And also, is there any encryption about the password?

THX for help