Variable Data Problem

The letters "hn" are being replaced with "Ú" in my output to a PDF.  It's not a consistent problem, and there seems to be no rhyme or reason to it. It's random.

Using Mac InDesign, and usually working with a CSV that comes from the PC side.  Usually a PDF generated from Satori mail software.  Not sure this is always the case though.  

Has anyone else exeprienced a similar issue?  It's been happening for a very long time here, and I would like to find out how to stop this from happening.  It a real problem on mailing jobs.  Any name, like Johnson or John, outputs as JoÚson, or JoÚ.

It's driving me nuts!

Any techinical Guru's out there that could explain this to me?