I'm sorry to revive such an old tread but i am having the
same exact problem for manga on my prs-t1 and i can't find a solution. I tried "sony landscape" which gave me near perfect result (full widht and correct aspect ratio) except the page is about 70% drawn and the rest isn't; it jump to next page on button because the reader simply cut everything below the screen. When i try the generic "sony reader" the result is far worse, in landscape theres 2 huge white margin with the small image in center and image is also cut at bottom.
If anyone can help me i'd be really gratefull, im such a noob at this.