I also have a 8GB microSD kingston I use via an adapter, I get about 1-1.5MB/sec sustained on it (and the internal card, too) when going through n810-usb cable, and ~17MB/sec when going through it's own tiny USB adapter. If you don't have anything crucial on it, I'd say reformat in the card reader on your desktop, and try it out then. If the speed is the same, that would rule out the NIT. If it fixes it, you likely had a corrupted filesystem.