I usually put the drive in an external USB enclosure when this kind of thing happens. Plug it into another computer and copy your data off of it (make sure you get it all). After that, run a couple of disk diagnostics (Check Disk then SeaTools) to verify that there's nothing wrong with the...
That happened to me earlier with an xml file I was trying to download. It was bizarre. I was glad I had a copy of Firefox around, which downloaded it no problem. I've found, when encountering similar inexplicable problems with Chrome, that reinstalling and/or deleting the user folder resolved...
I have the exact same problem, though I haven't yet ventured to open up my computer to check if switching headers helps. I have, however, noticed that there's an "Unknown Device" under USB Controllers in the Device Manager, which I suspect it's the card reader. I'll have to have a look at the...