When TViXiE obtains a movie cover from IMDB I have noticed it takes the image available on the title page, which is a very low resolution thumbnail.
( example (top left corner): http://www.imdb.com/title/tt0167190 )

Would it be possible to have TViXiE go one step further by actually retrieving the full size image available if you click on that thumnail?
This can be seen if you actually follow the thumbnails link as seen below, or by clicking the movie cover thumbnail manually in a browser.
( example : http://www.imdb.com/media/rm1839308032/tt0167190 )

I am not sure how difficult this would be to append to your already great software, I do think it would compliment your current layout nicely by displaying
a clear high resolution cover
os