Cant help you with reverting to a previous firmware (never tried), but would like to mention that the likebook has two time settings, one in the user settings thingy, one in the android settings (accessible via user settings, arrow right to the image of the ereader (at the top), and then android settings (or similar)), maybe setting both helps. Or not.
I had to reset the Likebook Mars (no books shown upon boot) and am just getting finished setting up all my android specifics once more - and all in all I love the new firmware especially the new default ebook reader/parser.
Feels like an entirely new device - thats also better using, the new 'both leds' feature.
(On the mars Im using custom with 1 pip on the blue led and 9 pips on the warm one - fonts are clearer with both enabled (diffusion layer properties, probably
))
Also, yes - the LED thing was probably the most notable new feature of the update.
For anyone looking for a quick guide on how I set up my android side of things, visit the mars thread, I'm writing a quick breakdown next.