microSD goes away after system reboot

we live in a place where nothing is stable. power outages happen that cause the device to reset.
unfortunately with that goes my web-proxy microsd setting.

i dont know why but when i re-enter the winbox program the web-proxy no longer shows microSD as an option.

i assume this is due to file corruption?

please advise.

i hate to bump this again but this is a real problem for me and its definitely causing me serious issues.

anybody?