When the firmware had a glitch that failed to properly close the database during USB export, I made a habit of rebooting the device before doing the second reconnect to transfer the subtitles and series information, and it helped. But as far as I know (I haven't really been paying attention to the recent firmware threads

) the glitch was fixed.
This
NickelMenu config will add an easy-access reboot button to the main menu:
Code:
menu_item : main : Reboot Device : power : reboot
I also had spontaneous database corruptions when the internal storage on my Aura HD started to fail.
EDIT: At least one user has reported the database-corruption happening with 4.40, which is only available for the newest devices:
https://www.mobileread.com/forums/sh...34#post4454934