1pw extension 3.9.19 in Safari 5.1.7 on Windows 7 is not locking. (Is there a different thread in this forum for Windows Browser Extensions?)
In the dropdown I'll click on the lock icon in 1pw and it will lock. But closing and rerunning Safari, click on the toolbar icon and 1pw just opens up!!! No password required.
PS: no problems in Chrome or Firefox.
I'm sorry that you are having some trouble, @JohnrC. I moved your post to the Windows category so we could better assist you.
Is Universal Unlock enabled in the extension's security settings?