The workspace never locks if you have the Edit Entry dialog open.
I know this issue has been reported before:
And I have read this:
So the main issue is what to do with unsaved data in the Edit Entry form.
However, since having the password database unlocked indefinitely just because a dialog box is open is obviously a bad thing from a security point of view, I have a couple of suggestions that might alleviate the issue:
1) If there are no unsaved changes, just go ahead and lock the workspace. Not need to worry about saving, since there are no unsaved changes.
2) Add an auto-save feature (option) so that when you exit the Edit Entry form with Ok, it always saves the changes. The same with new entries. With this in place, any time you enter the Edit Entry form there should be no other unsaved changes than the ones you might make in this form. This should make #1 above work a lot better, since there will more rarely be unsaved changes to prevent locking.
3) Maybe even add an option to always lock the workspace even though it will result in unsaved data being lost (with the proper warnings next to this option). It will then be the user's choice whether or not to use this feature.