I swear mine was the app. Had a Samsung SGS4g and Doubletwist used to turn itself on and search for a signal. I never registered for the service, so it would just search at random times, couldn't disable it as it came with the phone (Think it had Froyo on it, then TMO updated to GB) I was blaming TMobile for it and rooted the phone to delete it. It happened to others, mostly with Samsung phones.
Can't you disable it in APPS instead of task manager? I'm thinking the task manager might not be totally disabling it. Glitch in app communication?