hey, i was poking around old threads and saw your lock issue,, if you havent figured it out yet you can use Tot Lok like i do, works great and available all over the place
http://www.amazon.com/Safety-1st-Tot-Lok-Starter-Set/dp/B0000488W1
http://www.amazon.com/Safety-1st-Tot-Lok-Starter-Set/dp/B0000488W1