Verifying a certificate with Verisign OCSP Server

I'm attempting to use Verisign's OCSP server to verify a certificate that it has issued, for example, amazon.com

I have the issuer certificate (which was rather hard to find). As well as the amazon 0 certificate. I'm using openSSL but I don't seem to be able to get the right OCSP responder certificate to verify the response.

openssl ocsp -issuer test4-May2009Oc2010.cer -CAfile veri-ssp-intermediate-ca.crt -nonce -cert amazon0.crt -url http://ocsp.verisign.com

And this is the response:

WARNING: no nonce in response
Response Verify Failure
140735084268796:error:27069065:OCSP routines:OCSP_basic_verify:certificate verify error:ocsp_vfy.c:122:Verify error:unable to get local issuer certificate
amazon0.crt: good
    This Update: Jan 19 00:24:56 2011 GMT
    Next Update: Jan 26 00:24:56 2011 GMT

Any suggestions as to where the correct certificate for the OCSP responder might actually be?