New 5000T Very Hot And Screen Anomaly

Just bought a new 5000T and the first thing that I notice is that it runs very, very hot, so I was wondering if this was normal. The next observation is when switching between channels and the screen goes dark with the selected channel indicated on the top right of the screen there is a distinct moire pattern emanating from the top right corner of the screen that spreads out to just over a third of the screen. Once the new channel has opened and the channel number disappears then there is no more pattern visible, but I was wondering if anyone else is experiencing this. Other things that I have noticed is that it does seem to get confused quite easily and becomes unresponsive requiring me to disconnect it from the mains and restarting. I bought this to replace my 10 year old Humax 9200T, which does still work although rather clunky and forgetful, I kind of think that it has a better UI than the 5000T where you seem to have to perform two or three button presses on the remote where on the older box one would do. Any thoughts or advice gratefully accepted as I am seriously thinking of returning it, but wouldn't know what to replace it with.