I have problem with my WD caviar Black 750gb.
I never encountered anything similar to this behavior.

Hard drive has 0 bad sectors, and its surface seems fine, but when ever its on cold start, or hard drive temperature is somewhere below 37c , newly downloaded files or any hdd writes will sometimes have Redundancy Check Errors afterwards when Hdd tries to read those files.

Now I usually let HDD heat up to around 40c after windows boots up. Hdd smart will sometimes show weak sectors, but after I delete those bad files, its on 100% health again. My best guess is, hard drive's head maybe got used working on higher temperatures, and it gets a bit shrunk when its cold. Just my lame guess...

My real question here is, since its sometimes bother to lose over 5gb of file I downloaded, is there some sort of software that will remove unreadable sectors of a single file?

Thanks..