Mikrotik Dissconect

[f0rud]

Hi all.
Somehow I'm new in freeradius. and beacuse I live in Iran I can't access
this mail archive from web easy.(They are censored whole mail archive
and I don't know why!!) So I ask this here and sorry if its a duplicate
message :)

using mikrotik RuterOS and any thing is OK, the problem is Dissconnect.
I use this script to disconnect a user : 

#!/bin/bash
radwho -r -i -U $1 > /tmp/tmp-users-$1.txt
LOGIN=`cat /tmp/tmp-users-$1.txt |cut -d, -f1`
SECTIONID=`cat /tmp/tmp-users-$1.txt |cut -d, -f2`
NASADDR=`cat /tmp/tmp-users-$1.txt |cut -d, -f6`
rm /tmp/tmp-users-$1.txt
echo "Acct-Session-Id="$SECTIONID > /tmp/packet-$LOGIN.txt
echo "User-Name="$LOGIN >> /tmp/packet-$LOGIN.txt
cat /tmp/packet-$LOGIN.txt | radclient -x  -r 1 $NASADDR:1700 disconnect
testing1234
rm /tmp/packet-$LOGIN.txt

work fine, Mikrotik dissconnect user with successs BUT i get this :

Sending Disconnect-Request of id 107 to 192.168.0.6 port 1700
	Acct-Session-Id = "81400001"
	User-Name = "testuser"
rad_recv: Disconnect-ACK packet from host 192.168.0.6 port 1700, id=107,
length=36
rad_verify: Received Disconnect-ACK packet from client 192.168.0.6 port
1700 with invalid signature (err=2)!  (Shared secret is incorrect.)
radclient: no response from server for ID 107 socket 3

and then its try again (so I use -r 1 to prevent try again, just
once).Some said it woirks with 1.x (at mikrotik forum where I get this
script)  What happend to FreeRadius Client 2.X and I got this error?
need to check the result since its critical for my usage and I should
retry on fail but how can find this was a success or not???

Sorry if my English is very BAD :(