Cable Forum - COntrols on V+ box freezing

Hi there, looking for some advice here, please.
Several times now my V+ box controls seem to go strange, was going to say they stop responding but that aint strictly true. I can still use the remote or front of box buttons to move up and down channels, can still press OK and get small on screen menu, but if i press guide i do not get main menu, power button does not work either at these times. When i press buttons on remote, there is the small green light on the box flashes to indicate a command is being received but nothing happens. I know that the EPG updates usually around 1 in the morning but this has happened several times now at, say 9 at night, or this morning at 8, have to reboot to get control back. Phoned last week and had engineer booked, few hours later it started working again so i cancelled. Not sure now if it is a fault with the box or if it is some kind of upgrade or whatever going on at different times. When this happened last week it was like this for near enough 24 hours so dont think an upgrade t system is maybe the fault. Anyone had this same experience and got any ideas or solutions to it. Thanks again.