And I noticed that with several pdf´s there is a diffrent font size fromt he beginning and then it will be samller or bigger when I zoom. Oh, that sounded stupid... I meant... two books have diffrent size hen I open them for instant one have a fontsize 8 ! ande the other 4. and when I zoom I only need to zoom once with the first an three times with the second.
So if you need it big, convert them them, change the font and then put them back into the story =)