Security Failure Audits, 676, 677, 681

I needed to assign a group policy to my win2000 active directory, and following a case from this site, I created an OU, created the policy in the OU and moved all my users (50) from the users folder to the new OU (named User accounts).  I am able to login, but I keep getting Security Failure Audit events, 676, 677, 681.

I am afraid that I messed something up, that will cause me porblems in the morning when users start to login...  Did I do something wrong by moving the entire contents of the users folder to the new OU folder?

Thanks