An addition to this discussion.
I've just had my non-working with Xbox 2GB SanDisk Cruzer Micro USB 2.0 drive totally erased by a friendly soul with a PC of all pre-loaded software and anything else that was on it. Then reformatted to FAT32.
This was suggested as a possible method of getting a non-working stick, um, working
Definitely helped but here's the reason I'm posting: neither of my softmodded Crystal v1.6 Xboxes recognised the drive was attached when using the UnleashX dash. Best I had was a message that the memory card was faulty (MS dash) or couldn't be mounted (XBMC). It also seemed to affect adversely the loading time of XBMC (as a app) and the MS dash both of which initially, I'd estimate, took three times longer than normal.
But when I used it on a softmodded much older v1.1(0b) console the drive gave no such trouble. It was immediately recognised by all those dashes and most of the time works fine for small size (<10 blocks) game save transfers to and from.
It also works sometimes for slightly larger files but those which don't and anything I've tried above 35 blocks give a copy failed error message. Usually this requires a Shutdown to reset. A simple reboot and the drive just disappears from all dashes or is sometimes shown by UnleashX File Explorer as not being formatted or presents as a corrupt text message.
The drive is effectively useless as it just can't be considered reliable. However, the interesting point is that the erasing/reformat of the drive did have an effect (none of my Xboxes recognised it before) but another factor: the Xbox version being used, seems to be important as regards USB drive compatibility.