Early into the developement of the Windows Mobile version of SportyPal, we noticed an interesting feature of the operating system that bugs us to this day: even if there is work actively being done by an application (such as, for example, recording the coordinates of a GPS-tracked workout), the device will go to sleep mode if it’s set to do so and you don’t press any keys in the meantime. Unfortunately for us, sleep mode also kills the GPS signal, and we don’t want this to happen during a workout. To work around this without having to tell the users to change their power settings for every workout, SportyPal disables sleep mode during workouts (where having a constant GPS fix is obviously pretty important) and handles the screen state itself. So far, so good. But there are two problems that remain:
First, if you press the power button to turn the screen off, the device goes to sleep and your signal is lost. Don’t do this during a workout, the screen will turn itself off pretty soon, and you can turn it back on by pushing any button on your device.
Second, unlike the devices that we tested on, some devices completely ignore our attempts to disable sleep mode and sleep anyway. Over the next few CAB updates, we’ll be looking for a way to disable sleep mode for all Windows Mobile devices. However, since we can’t test if this works (we haven’t had any problems with this on our devices to begin with), we’ll need your input to tell us if what we’re doing is any good.
Until we sort this out, users with the auto-sleep problem are going to have to set their power settings manually. To do this, go to Start -> Settings -> System -> Power -> Advanced and uncheck the “turn off device if not used for…” option.

Power Settings