The mechanism for unlocking a password protected screen saver does NOT check to see if the account is locked out.
If you account is locked out, the default unlocking behavior will still accept a valid password and unlock the screen saver.
One downside of this behavior is that if the computer is locked, and the account is locked, a successful break-in will NOT register a 528 event in the Security event log.
To workaround these behaviors, Copy / Paste the following entries to a <Drive:>\Folder\ForceUnlockLogon.reg file and run regedit /s <Drive:>\Folder\ForceUnlockLogon.reg:
REGEDIT4 \[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\] "ForceUnlockLogon"=dword:00000001