Nsupdate failed to update

Hello all,
I am new to Unix.. i am trying to implement the TSIG in my BIND and using nsupdate to add record to bind..

this is what i did:
generate the TSIG key using : dnssec-keygen HMAC-MD5 -b 128 -n HOST mydns.com

forgot to mention: i am using FreeBSD.

I then edit the named.conf file in /var/named/etc/named with this value :
zone "customer" {
type master;
file "master/customer";

};

Key update.1.168.192.in-addr.arpa.{
algorithm HMAC-MD5;
secret "DPgvulv4e5KLE1ZGqYS61g== ";
};


zone "1.168.192.in-addr.arpa" {
type master;
file "master/1.168.192.in-addr.arpa";
allow-update {key update.1.168.192.in-addr.arpa.;};
;

i then stopped named and restart...

then i issued the command admin@root# nsupdate -d -k /usr/sbin Kmydns.+157+55558.private

i typed update add customer2.mydns.com 86400 A 192.168.1.1

then typed send.

however, i got this error message :

;; TSIG PSEUDOSECTION:
mydns.com. 0 ANY TSIG hmac-md5.sig-alg.reg.int. 1224739169 300 16 VkNx6gEY6PobdUcAwu8r3g== 29090 NOERROR 0

; TSIG error with server: tsig indicates error

Reply from update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOTAUTH, id: 29090
;; flags: qr ra ; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 1
;; TSIG PSEUDOSECTION:
mydns.com. 0 ANY TSIG hmac-md5.sig-alg.reg.int. 1224739169 300 0 29090 BADKEY 0

Is there anything i have missed?

please help

Audre