I have a simple app I wrote to debug another gps issue here:

http://developer.appcelerator.com/question/71611/gps-cuts-out-sporadically-android

On further exploration if I make that window a "heavyweight" window, then the GPS will never turn on and activate. Here is the original code http://pastie.org/1233923 to see the problem add "navBarHidden: false" to the window properties and run again, and the GPS will never activate or fire.