unfortunately whith the new 32 gb ultra micro sd sandisk, but it took longer go back , i have the same problems but more spaced, index service stopped and refreezes screenen, although the application does not appears to cause battery drain, thing it was before.
Obviously i think is not a problem to corrupt pdfs, but a problem in operation index service program in this phone with this android 4.3, because this problem never happened in other phones (S3, note 10.1, with the same pdfs files).
I think the problem will be not solved till samsung took a patch to fix it.
It,s a shame that after more than a month, as big a problem as it has not been solved.
I have already extended this problem in various forums and i think the rest should do the same, because as long as people keep thinhing tha N3 is a marvel phone whith no serious problems and willing to buy , samsung did not care to fix it.