Linux To ADS: correct time, but "Clock skew too great .."

[Sonja Benz]

Hello,

I try to set ab Kerberos authentication for a Linux client to ADS. The 
behavior is strange: Obviously the client communicates with the ADS 
server, e.g. I get an "Preauthentication failed while getting initial 
credentials" if entering a wrong password and the password is locked after 
entering repeatedly a wrong password. However, "kinit" never successes, 
but when entering the correct password says "Clock skew too great while 
getting initial credentials". Surely we did check the time at client and 
server. It is correct! 

Any ideas, what else could be wrong and give this error message?

Sonja