List Export question

Hello all.  I'm newly learning the Development side of Tessitura.  I've run in to a small issue since our most recent update.  Once I create a basic list, and export it in to Excel, in some fields that would remain blank, the export is causing the word "null" to appear.  It's not consistent, unless I'm missing something.  As I said, I'm very new to this and no one in the building seems to have an explanation.  Can anyone assist?  bnoffe@thefulton.org if you'd rather email me directly.  Much appreciated!!! Brian