Sometimes my AAO becomes unresponsive and doesn't work until I get it in the foreground. Then it works a couple of minutes again. 

Maybe someone have a hint for me?

Sorry, no idea. Sounds odd though. Are you using some kind of "optimizing" tool for your PC that might decide that AAO is not worth executing?

Just in case, make sure to check your device blacklist and "Ignore" all devices that you are not using with AAO.