I was able to dump New Super Mario Bros. flawlessly. Below is some basic info.
Code
< ROM Information > Game Title : NEW_MARIO Code : NTR-A2DE Ver : 00 Maker Code : 01 Unit Code : 00 Chip ID : C2 1F 00 00 ROM Size : 256M (32MByte) Used : 19.65MByte
< SAVE Information > SAVE Type : EEPROM 64K (8KByte)
$ from NDS Backup Tool FTPd v0.1
Used FFFTP, here's the transfer time:
Code
>RETR /NEW_MARIO_A2DE_00/NEW_MARIO_A2DE.nds 150 Opening BINARY mode data connection for '/NEW_MARIO_A2DE_00/NEW_MARIO_A2DE.nds' (33554432 bytes). 226 Transfer complete. Download successful. (3632 Sec. 0 B/S).
So transfer time was 60.5min for a 32MByte cart. No clue why the speed says 0 b/s. During the transfer the speed hovered around 9.6 KB/s (Started at 30 or so.) Hope this is useful.