Try a power off & reboot, standard fix for most unexplained issues. Now have my box fitted to a timer to power-off/on at
4.00 am every day. Not sure why we all assume the STB should be on 24/7 and not given the chance to be refreshed by periodic reboot, same as we do with PC's and laptops. Tommo 004 (2006) box with no mods - still going strong, with only minor hiccups!...