Unlock of computer does not update kerberos credentials

I have my 10.7.5 machine joined to an Active Directory domain. Kerberos and single sign on work well except for one problem. When I unlock my machine in the morning I notice that I have to run kinit manually to refresh my credentials to get single sign on working properly. Looking at klist before I run kinit shows that my credentials have all expired. On a Windows 7 machine tied to the same machine, simply unlocking the screen will also refresh the kerberos credentials. It is much more seamless. Can we replicate the behavior here as well? When I unlock my machine, can we get the kerberos credentials updated as well?

Thanks,

Scott