calling $ ec2-describe-instances -K key -C cert I get

Unexpected error:
org.codehaus.xfire.fault.XFireFault: General security error; nested exception is: 
	java.security.cert.CertificateException: Unable to initialize, java.io.IOException: insufficient data
	at org.codehaus.xfire.fault.XFireFault.createFault(XFireFault.java:89)
	at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:83)
	at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:114)
	at org.codehaus.xfire.client.Client.invoke(Client.java:336)
	at org.codehaus.xfire.client.XFireProxy.handleRequest(XFireProxy.java:77)
	at org.codehaus.xfire.client.XFireProxy.invoke(XFireProxy.java:57)
	at $Proxy12.describeInstances(Unknown Source)
	at com.amazon.aes.webservices.client.Jec2Impl.describeInstances(Jec2Impl.java:1296)
	at com.amazon.aes.webservices.client.Jec2Impl.describeInstances(Jec2Impl.java:1271)
	at com.amazon.aes.webservices.client.cmd.DescribeInstances.invokeOnline(DescribeInstances.java:58)
	at com.amazon.aes.webservices.client.cmd.BaseCmd.invoke(BaseCmd.java:856)
	at com.amazon.aes.webservices.client.cmd.DescribeInstances.main(DescribeInstances.java:67)
Caused by: org.apache.ws.security.WSSecurityException: General security error; nested exception is: 
	java.security.cert.CertificateException: Unable to initialize, java.io.IOException: insufficient data
	at com.amazon.aes.webservices.client.CryptoProxy.getCertificates(CryptoProxy.java:76)
	at org.apache.ws.security.message.WSSecSignature.prepare(WSSecSignature.java:291)
	at com.amazon.aes.webservices.client.Jec2Impl.signRequest(Jec2Impl.java:233)
	at com.amazon.aes.webservices.client.Jec2Impl.access$000(Jec2Impl.java:66)
	at com.amazon.aes.webservices.client.Jec2Impl$1.invoke(Jec2Impl.java:145)
	at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131)
	at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:79)
	... 10 more
Caused by: java.security.cert.CertificateException: Unable to initialize, java.io.IOException: insufficient data
	at sun.security.x509.X509CertImpl.<init>(X509CertImpl.java:199)
	at sun.security.provider.X509Factory.engineGenerateCertificate(X509Factory.java:107)
	at java.security.cert.CertificateFactory.generateCertificate(CertificateFactory.java:322)
	at com.amazon.aes.webservices.client.CryptoProxy.getCertByName(CryptoProxy.java:116)
	at com.amazon.aes.webservices.client.CryptoProxy.getCertificates(CryptoProxy.java:74)
	... 16 more
Caused by: java.io.IOException: insufficient data
	at sun.security.util.DerInputBuffer.truncate(DerInputBuffer.java:125)
	at sun.security.util.DerValue.<init>(DerValue.java:279)
	at sun.security.util.DerInputStream.getDerValue(DerInputStream.java:417)
	at sun.security.x509.X509CertImpl.parse(X509CertImpl.java:1725)
	at sun.security.x509.X509CertImpl.<init>(X509CertImpl.java:196)
	... 20 more