Java Security

i am trying to import a certificate to c:/java/lib/security/cacerts.

i have to add a new certificate into cacerts.

but i dont remember the .keystore password.

keytool -import -trustcacerts -alias name -file "C:\newcertificate.crt" -keystore "C:\prog.files\java\jre1.6\lib\security\cacerts"

i tried default password: changeit

i got this error message:

key tool error: gnu.javax.crypto.keyring.MalformedKeyringException: incorrect magic

So, how can i add the new certificate to cacerts ?

NOTE: I have a second certificate on my server. And i have already added certificate 3 months ago.
So, deleting the keystore file may can cause the second certificate not to work correctly?
Now i dont remember keystore password. So how will i add the certificate without deleting the keystore file ?
And i work on linux platform. (as you know java doesnt care about platform)

a. if i delete keystore password, my old certficate works correctly ?
b. how can i reset keystore password ?
c. *"how can i add the certificate to cacerts?" this is the main problem.*

what i tried to do is failed :
1. Copied a new keystore from an other pc to my server and replaced with old keystore >> MAC ADDRESS FAILED error
2 Copied a new cacerts from an other pc to my server and replaced with old cacerts>>keystore password problem still goes on

Waiting for your answers as early as you can! thank you...

Edited by: weblogic_admin on Aug 19, 2010 10:41 PM

Edited by: weblogic_admin on Aug 19, 2010 10:41 PM

Edited by: weblogic_admin on Aug 19, 2010 10:42 PM

Edited by: weblogic_admin on Aug 19, 2010 11:27 PM