The picture will freeze when I try to rewind live tv and also the tv picture will freeze for 5 seconds or so when watching any digital channel via Sky and then reset it self. This happens atleast once per day.
It could be a corrupted file system or buggy software.
The first step would be a simple reboot, put the box into standby and when the drive has spun down turn the power off at the plug, count to 10 and then turn it back on.
If this doesn't help then the next step would be to reload the OS.
This procedure is done at your own risk
Hold the backup button down on the box while turning the power off at the wall socket.
Wait 10 seconds and then turn the power back on WHILE STILL HOLDING DOWN THE BUTTON and then wait for a message on the screen or all 3 lights on the front of the box to light up, then release the button.
The new software will take around 10 minutes to download and then the box will reset it self and stay in standby, wait another couple of minutes then turn it on with remote or the button on the box and you should be away.
If this doesn't help then the fault could be with the actual hardware (STB, cable connections, cable and/or LNB).