There are so many different models I can no longer make heads or tails on which will work and if it's possible to go higher than 1.5 on firmware. I want to read my Kindle stuff but it only allows 1.5 firmware. Model number: sdkDemoFirmware version: 1.5Kernel version: 2.6.25 rockchip version 1.2.7 (ruiguan)Help? Thanks!