Genral Journal VAT versus NO VAT

Good morning. My client is on Sage Pastel Partner Version 18. He uses the General Journal just about every day. When he logs in the DC is showing, he then clicks on Settings and removes the tick from the "Tax Processing" box. When he returns to the General Journal the next day to process the DC column is back and he has to keep on changing the settings, which is very annoying. Is there a  fix for this please ?

Thank you and regards

Marisan