Some of our users have started to use one of our customers SharePoint team site, they log on using their email address as the username and a password issued by the customer.
When they access the team site, they receive a standard windows login box, no option to save the password or not. After logging on and after a few minutes their account in our AD domain is locked out.
The email address is an acceptable username in our domain, so our theory is that the login information is saved/cached and then used as default on all authentication attempts (alot of which occurs in the background)
Seems that each activity (login, opening a document, changing folder etc) performed on the web site is causing 1 bad password attempt.
Security log on the dc shows the following:
675,AUDIT FAILURE,Security,Fri Sep 10 12:26:53 2010,NT AUTHORITY\SYSTEM,Pre-authentication failed:
Any ideas on how to solve this?