I have created an app using the commonJS spec. Using instruments the live memory is approx 3.5mb once the app tabs are loaded.
When i use take photo, either with allow editing = true or allow editing = false, i receive a memory warning and the next touch event will cause the app to blank out and you have to reboot.
Let me know if you need more information but there isn't much more to say. I haven't had this happen in other apps i've used.