All the inactivity mode does it prevent the hard drive from spinning after four hours. If anything it might prevent EPG data from getting to the hard drive unless they have it programmed to spin up if it detects data is coming to the receiver. I have not had any issues with my 721 getting EPG data even while the receiver is on. When the receiver is on around 3 am EST I can hear it working and this leads me to believe that it is downloading updated EPG info.