I seem to have come across this problem a few times, but I can't consistently reproduce it. I happen to use file operations like copy/paste/cut/delete a lot and every once in a while something weird happens. A few examples:
P.S. I never had problems doing all this using original firmware...
- I was deleting files one by one and suddenly one file was not deleted but stayed there with a generic 'Save' icon even though it had extention of just NDS. I tried deleting that several times and bang - the full folder was just emptied (I had 100+ files in there)...
- I was doing cut/paste and file was moved but was showing generic 'Save' icon in the destination folder as well and could not be loaded. I looked at the file under windows and it was 32K file instead of 16Mb that it was supposed to be.
P.S. I never had problems doing all this using original firmware...










