Getting error in pkinit

[sasikumar bodathula]

Hi,
   I am using kerberos5 with pkinit support generated certificated with steps mentioned in MIT sites and when trying to get authenticated from KDC getting following error in the KDC log file

preauth (pkinit) verify failure: Inconsistent key purpose
Inconsistent key purpose

What is the meaning of this error and is there any problem with the certificates or KDC or client picking the wrong certificates?

Best Regards,

B.Sasikumar.