I'll be using FFVI as an example. This game is being played on an actual cart on my SNES.
My PVM displays some games in odd ways, changing how they're viewed. Lets start with the first image. The title screen of FFIII. It displays how it should, it fills the screen, no issues.

However, when walking around in towns, the image doesn't fill the screen anymore, there are black borders around the picture.

I highlighted the area where the image doesn't fill.
So, it would be one thing if the image just stayed that way, but it doesn't. In random battles, the viewable area in the center shifts up towards the top.

And again, on the world map, the image is displayed in a different way as well. This time it fills the screen vertically, but there are black bars on both sides.

Now, does anyone have any idea why it does this? It would be fine if the image just displayed one way and stayed there, but having the image constantly shift around drives me insane.
I've noticed this type of thing with other games. FFII (SNES, played through Wii emulator), and Dragon Quest III (SNES, played through Wii emulator) also have this exact same behavior. In addition, Hey You Pikachu displays as a tiny box in the middle of the screen, and Mischief Makers displays as a tiny box shifted all the way to the right, with borders on the top, bottom, and left. Here's the thing though, I know for a fact that Hey You Pikachu and Mischief Makers once displayed as they should have, filling the screen with no borders. It's like one day this issue randomly started appearing, and to my knowledge, no settings have been changed within the PVM, it just started happening one day.
I use this PVM to play all of my consoles. PS1/PS2, Gamecube, and Wii have all displayed games with no issues at all, and all of my other N64 and SNES games don't have this issue. Stuff like Earthbound and Dr. Mario 64 plays perfectly fine, but it seems there are select games that display in this weird way. I'm aware that most systems will display in different ways, and this I can see and it isn't an issue, but I don't really understand why certain games will display fine, but then playing different games on the same system displays awkwardly, and it's even more of a mystery since two of the games that previously displayed fine have also started to exhibit this odd behavior.
My first thought was that it was possibly the cable being used, since I use the same one for my SNES and N64, but that wouldn't really make sense as most games don't have this issue. Another thing, some SNES games that I've seen with this issue are being played through an emulator on my Wii, meaning that the cable definitely isn't the problem. I'm aware that I can go and adjust the way everything displays with the PVM, but considering that I use this PVM to play all of my systems, changing these settings would be silly as this isn't an issue with 90% of the things I play.
And before anyone asks, I've tried both overscan and underscan.



