in the current development version of BrailleExtender, In the combo boxes of the preferred input and output braille tables, there is an option automatic braille table. Unfortunately it is always marked as checked and I can not uncheck it from my preferred input and output tables. more precisely saying, i can uncheck those checkboxes and they will be shown as unchecked. then i press OK and restart NVDA and my changes will not be saved. this automatic braille table will be selected again in those combo boxes of prefered input and output tables.