@outismetis: W00t! Thanks for the feedback!
Since you've installed the fonts hack, could you zip up and post the content of the linkfonts/backups folder? I'd like to see if the fonts have been updated... Thanks!
@seagull: Er, if the jailbreak update didn't fail, I'm assuming it means that your Kindle already was jailbroken? (never really tried, but that's a bit weird...).
And what do you mean exactly by 'doesn't work'? Did you put the full linkss/ folder in the root of your Kindle?