hi i just recieved a phonecall from amazon, i was told to press menu, settings then menu again. then select reset and this fixed my problem (ive only had mine 2 weeks and for some reason never considered this:P)
Woah, woah, woah!
That is the "Reset to Factory Defaults" option! I'm not saying that it might not be eventually necessary, but that should always be the last option you try. If you've only had your Kindle a little while, then it's certainly no big deal, but those who have had theirs for quite a while may be dismayed to find all of their books gone... not to mention all of their customizations and hacks.
That is the ; "let's just start all over from scratch" option... and not to be taken lightly