Thread:Extension talk:LDAP Authentication/Some users unable to auth via LDAP some can?/reply (12)

No this was not LDAP enforcing password policies. If that had been the case then the test users would not be able to login to other services that use LDAP for authentication.

I think this is a bug with MediaWiki or the LDAP Module. Not sure which. strace output seemed pretty useless when I tried to debug.