Hi Allocator,
Regarding your posting about making copies of MyLog.db3 and NavData.db3, I've just looked in my Data folder and found that there is also a MyLog.db3.bak and a NavData.db3.bak file with only a few minutes difference in the date and time, both of them more or less the same size as the .db3 ones.
Are these automatically produced back up files and if so, is it necessary to make another one in a similar form to your suggestion above before deleting the MyLog tables?
regards.