Hello Phil,
I'm afraid there is no way how to fix this, because the links are not same in fact, as you can see from the different itemID. It would be theoretically possible to ignore it, Thbut then the original Joomla functionality would be broken (after clicking the link you would be always redirected to certain article -- now page will stay on current article).
Second option would be to have the URL just partially optimtized, that means keep the lost-password part and just add itemid=xy.
Any of this changes would need to be done in the JoomSEF core, but we do not plan to do so, as we consider the current behaviour the best one, even of not perfect. (but there is seldom really perfect solution without any compromises)
Best regards,
Jirka