Manual text in balloons switching to a question mark on rebuild

Hi,

I'm using balloons for a specific purpose to indicate something on a drawing. They are not connected to any table, BOM or cutting list.

So I am using the "Text" in Balloon Text and inputting my own letter into the balloon. Works great until I rebuild the drawing, the text I entered reverts to a question mark.

Any ideas? I thought the Text choice from the drop down menu was exactly for manually altering balloons...

SolidworksDrawings And Detailing