Transmission

I've been using Transmission for a while and feel fairly comfortable with it, and respect it enormously (Tried some others). But I am no expert and won't be surprised should I be told off in this forum.
It's been going on for a while. I notice that My fully downloaded torrents start losing small to significant portions of their data files. Sometumes I can just verify and the indicator will then back to blue and get the missing parts back- but is there a solution to this? Is there something I can do to safeguard these bits o' data.
Gratefully-
J

Wow, how does one mitigate/eliminate this?

I always seed as long as possible, but in th ecase of say- music files, I often change them (Metadata, etc). So is it then a better olivy to copy the files and leave them on their own to seed, using the copies for my purposes?
Gratefully-
J

OK, new development/mystery (To me).
Twice, now I've verified the data and watched in horror as more than half of the data disappears from the progress bar. Is this MY nincompoopery, or is it one corrupted sector making the rest useless?
Thank you by the way for the proffered wisdom.
J