Stuttering on Catch-up with 256

After many issues with my Z-Nano STB and paid subscription I was given a Mag256 instead.
happier with this box The EPG miles better and its seems faster when loading, however Whenever I leave the Mag on and and just listen to my radio when reverting back to TV the Mag has either switched off or wont start up until I reboot the box.

The other issue is when watching catch-up the programme often jumps or stutters or pixilates and occasional finishes before it actual end of the programme.

I had the same issues with the Z-Nano so is this all down to my iptv provider (who incidentially vehemently denies its their issue but blames my isp company)

Have I just chosen a bum iptv provide or is there an issue with both boxes?

And now everytime I leave the box on standby it will not switch back on unless I reboot the box. All that happenes is that it keeps reloading then going back to standby
Getting very frustrated with it all