Server image banner getting stretched

I really don't understand why it stretches your server image out. They say to use 512 x 256, but then it stretches it to an even bigger size and butchers the quality, it doesn't make any sense. Does anyone know why it's done this way and know if there's something that can be done?

 

Server header image is working fine for me, where are you uploading your image to?

 

If the image was small to start with and you made it bigger then yes it will look stretched. There are websites out there that will make your image what size you want without stretching it

 

I made it the size FP tells us to from dev blog #75, as well as all the other comments I've seen about it here on the Oxide forums.

Here's the size they tell us to upload.

What it turns into when you upload it in said size.

I've tried making it that same size that it stretches it out to be, but it won't show up if you do it that way.