Java Security

I am trying to use SPNEGO + JBoss 7 + Windows 2008 R2 + JDK 7, but I am getting this exception:

Unable to authenticate - Failure unspecified at GSS-API level (Mechanism level: Checksum failed)

I created the keytab:

ktpass -ptype KRB5_NT_PRINCIPAL -crypto All -princ HTTP/win2008@TEST.COM -mapuser win2008 -pass *** -out krb5.keytab

Any ideas?

Thanks