It is interesting, but in opie-reader I see (after selecting correct document encoding) all characters correctly except character š and ž. š is displayed as s character and ž as z character. Never mind if encoding of document is in iso-8859-2 or win cp1250. I have selected font standard dejavu-sans font - all other don't show any correct czech characters or have same problem.
I think it have to be font problem, but I can't find font with correct characters. May be it have something to do with fact that iso-8859-2 and cp1250 are different exactly in this 2 characters.