Well, just uninstalling didn't help, still no interval option is available in background menu. I didn't installed any other oem apps, 'cause I did a reinstall recently. Anyway, It works, in a little strange fashion, but nevertheless, it works. Maybe if i find more time I try to do something with it. I still have an original partition image from Asus, to recovery, but I leave it for now. Thank you all very much for help, but if you still have some advices, don't hesitate to share