There is two options for you that I can think of straight away:
When you are in the movie section inside MP, refresh IMDB (either F3 or F9 and then choose IMDB) then in the movie overview you can select from a number of different movie posters
If that does not help, you need to close MP and go into Configuration, inside Movies and then inside Movies Database. There you can choose the Title you want to edit. Click on Coverart tab and there you can either point to the URL of the correct image, or browse to a local file
Just to add to what Furetto said, BACKUP your MP folder to somewhere safe, it can be a real pain reimporting all your Movies once you have finished doing all your updates\configuring, this will allow you to restore individual or mass settings.
So, you're power cycling the TV, but not putting the PC to sleep ?
In General => Startup/Resume settings, try checking "Ignore Windows resolution/size changes"
In Codecs and Render, try selecting the specific audio device rather than "Default DirectSound device"
Just ideas, no guarantee this will do anything.
If this doesn't work, I...
So, you're power cycling the TV, but not putting the PC to sleep ?
In General => Startup/Resume settings, try checking "Ignore...
I'm running MP1 as a client only on this:
https://www.amazon.com/dp/B0DZX5DWS5?ref_=pe_123509780_1038749300_t_fed_asin_title&th=1...