Certain Task Killer apps, Battery Saver apps, and device settings can conflict with the Lookout app.
In some instances the presence of an automated Task Killer app (e.g. Advanced Task Killer), 3rd party SMS program (e.g. Google Voice or GoSMS), Memory Optimizer (e.g. Memory Booster), and/or Battery Saver (e.g. Juice Defender or power saver modes included with your device) can prevent Lookout from functioning properly. These apps and device power saver modes cause issues particularly for remote commands, such as Locate, Scream, and Restore. We advise that you either remove these apps from your device or set them to allow Lookout to function, and set power saver modes to OFF in the device settings. Many apps of this type have a setting for users to "allow" specified apps (in this case, Lookout) to function without impediment. Please contact the support department of your particular Task Killer or Battery Saver app if you have trouble doing this.