Burms and small kids, sounds like you do need to review your safety procedures and cage security.

We're in the process of adopting our biggest snake yet, an 8 foot female boa. She won't get of course as large as your Burm will but with an active 6 year old in the house plus teenagers we've decided on a number of security devices. Her enclosure is a custom built deal and features two locks plus a wireless door alarm as shown in this link (item #04-101).

http://www.mypreciouskid.com/wireless-door-alarm.html

For $10 I'll have the peace of mind knowing I'll hear an alarm if any of the kids manage to get her door open. It may be overkill to some folks but for me, I think safety and bigger snakes just can't every be "too much".

I hope you find this snake soon.