SSL certificate via keytool

I am using WM 9.7 and trying to generate cert,keystore,trust store for my POC purpose

Threads :-
http://tech.forums.softwareag.com/techjforum/posts/list/0/55162.page#204736

Followed all steps mention in this threads but i m getting struck at step 9
Kindly share knowledge

I have generated certificate,public key and trust store for server1 and server2 as per the commands mention above
BUT
While I am trying to combine both public certs to the trust store as per the commands mention in Step 9

Combine

Step 9: Add both public cert to the truststore .
keytool -import -alias Server1 -file D:\Certificates\Server1_publickey.cer -keystore D:\Certificates\Server2_trustore.jks ( This command is working good BUT 2nd commands failing with below exception)
keytool -import -alias Server2 -file D:\Certificates\Server2_publickey.cer -keystore D:\Certificates\Server1_trustore.jks
keytool -list -v -keystore D:\Certificates\Server2_trustore.jks

Exception while combining both public certs to trust store? Pls explain why it’s failing or how to combine both public certs to trust store ?

D:\webMethods\jvm\jvm\jre\bin>keytool -import -alias Server2 -file D:\Certificates\Server2_publickey.cer -keystore D:\Certificates\Server1_trustore.jks
Enter keystore password:
keytool error: java.io.IOException: Keystore was tampered with, or password was incorrect

Note : password used while generating cert is same and correct, so i don’t believe it was failing bcoz of password issue

Did any one face this issue while combining both public certs to trust store ?