made the mistake of starting off with my ipad 2 by building files through emailing pdf not itunes. using either ibooks or good reader and others if various files didnt open in either of those. if i replicate this will erase all that of the above. is there a 3rd party resource that can save most of these so i can upgrade to io 5? it might be simpler to just start over again with a new ipad( or windows os). some of these files will only print not export to another app.