After using Gparted under Linux to format the internal storage of Arnova 10 or any Rockchip 2818-like tablet (e.g. Apad), your internal storage can be un-recognized by the device and consequently your SD card cannot be mounted.
Solution: reformatting the internal storage into FAT32:
1. Install android-sdk (and drivers if your using Windows) on your Mac or PC computer
2. Connect aPad via USB to the computer and don’t mount flash cards
3. Open terminal and start adb with “shell” key.
4. Serach inside /dev/block on the aPad for the internal flash storage (For me it was a /dev/block/vold/31:8)
5. Run reformating by the “mkdosfs -F 32 /dev/path_to_the_storage ” command (for me “mkdosfs -F 32 /dev/block/vold/31:8”)