[Samba] Login Accounts not Caching

[Eric Haberman]

- Samba ver. 3.0.22
- Kernel 2.6.5-7.193-smp #1 SMP Wed Jul 20 14:39:18 UTC 2005 x86_64 x86_64 x86_64 GNU/Linux
- Samba as the PDC with Win XP clients logging in
 
Our domain has been functioning without a hitch for 1 year, we have 1 PDC on Suse Linux, and 3 BDC's also on Suse Linux.  Yast was used for most of the configuration.  
Starting last week our laptop users that work from home at night and had been using cached accounts started getting the "Domain not available" message when trying to log in from home.  This is not a cache expiration issue, but rather the login cache being destroyed when logging in at the office.  If I change my password in the domain all of a sudden the account starts caching again... but I don't want to force everyone to change their passwords and who knows how long it will last, maybe the cache will stop working again tomorrow!
 
Has anyone experienced this before?  We haven't changed anything on the server side, but its possible that a MS update has hosed us..... just throwing thoughts into the wind.
 
I have tried changing the cache setting in the XP registry to 50 from 10 - didn't help
I setup a local policy that doesn't require server signing or any sort of secure channel to the DC - didn't help
I ran pdbedit and set the expiration dates for the passwords to 2037, worked for a small amount of time, but did not fix the problem, after a couple of logins the cache would break again - didn't help