I purchased the new Canon VIXIA HG21 AVCHD 120 GB HDD Camcorder, and the Nexto Extreme. They don't work together for USB OTG, for backing up videos from the hard disk; is there a planned update for your software?
The camera does backup photos when it is set to view photos; but when set to view videos, the Nexto says unsupported USB device. In order to make backups of videos, I need to select each file individually on the Canon, copy to the SDHC card on the Canon, then insert the SDHC card into the Nexto Extreme. This is a slow process that takes about an hour of manual work.