djviewer behaviour

hi I'm using a 622 touch

all the djvus I made are well displayed.

all the djvus got from here http://archive.org/details/texts are shown half of the page well and half a little darker
i can still see it but is annoying

exactly it makes an orizontal cut off of the image displayed, the part above is ok and the part below is darker. If the image doesn't fit the screen it has the same pattern for the portion of the image shown after

any clou?

thnks

paolo