Thumbnail Image Issue

Hi there I was wondering if anyone can help Im trying to get the artwork for my movies/tv shows but when I do it comes out all blurry. I use photoshop to create the image then save it as the correct resolution at the highest quality but its still blutty in the gallery mode. I know this can be done as I use the WDTV Hub Gen to import movie info and images and their quality of the images are perfect but if I want to add an image for the folder manually it goes wrong.

Any help would be greatly appreciated

Hi, the link below might related to your question. 

http://community.wdc.com/t5/WD-TV-Live-Hub-General/Thumbnail-resolution/m-p/201808/highlight/true#M10716