Also, I have found that the tablets react really scarily to being out of memory. You might just have to delete some images or something and the frightening situation will magically disappear. You will have to learn how to navigate a bit in Xterm to find the files and delete them. Once the scary messages go away, you can delete a few programs for a much longer-range cure, and for a permanent cure, booting from an SD is the ticket. You can live happily without booting from an SD, however, by not going totally hog wild installing programs.