I have read that the internal, differing and variable management systems in flash drive is not made to use regular "defrag" tools. Do not use the Windows defrag tools on your flash drive. I don't know if it's every time but I tested on my USB drive and MicroSD drive and I think it set up a time bomb effect where I had to reformat the drives. They work fine now (Never forget your backups). I don't even think flash drives benefit from a defrag process, like a spinning hard drive does (a little). I wasn't sure where to post this but I hope fellow DSTT owners do not defrag and then think they have obtained or developed bad flash drives. What does your experience indicate? I noticed that the "dsorganize" folder (looking from that file browser; on the DS) CHANGED when it started giving error messages; about non patched files (which were DLDI patched and working). It then displayed as "DSORG~1" (or similar, first few letters; now all capitals with the ending ~1, as Windows does in DOS.) It was and is now back to lower case (working) now after reformating. I am reasonable sure that defrag (else simple copy and paste type maintenance) caused a change that developed the problem. If not, my flash just give up own it's own. I don't think that is as probable. What do you say? The net suggests, NEVER defrag flash drives. Had you heard that? Is this the cause of so many flash problems? FYI. I wonder if checking (scandisk. Don't do it.) a flash disk (from Win XP fully updated) is safe (when alterations are made)? I mainly use Kubuntu with no DS or flash problems. It seems that using Microsoft tools (via XP Pro - current); for Microsoft FAT files systems (on flash drives) was a bad idea. Silly me.