The HAM does know little about linux ! The limitations you are facing are the reserved blocks in a Linux file-system on the partition /dev/mmcblk0p2, where /home is.

Do you use Nitdroid to clutter this space? Or do you have some large files in /home/user, that would be possible to go to /home/user/MyDocs? To analyse, please post the output file of Note there is no small L in the command but a 'pipe' symbol.
This command will list the files and folders under /home sorted by the size of them, and writes the output not onthe screen, but in a file called for du.txt in your MyDocs folder. Please attach the file to the next posting.