I just discored in a very unfortunate way that simply pasting text to a cell without typing anything else does NOT save its content the next time you open the translator.
Viewing post in Community Translater V1.0 comments
I may have fixed that in the v1.1. Make sure you have the latest version :)
Oh and though the program save every time you change cell, I advise you hit the save button to be sure. But if you think it's something else (like a bug for instance) don't hesitate to give me details on how it happened. I'll fix that and post an update :)