I recently jailbroke my iphone 4, and was successful. I downloaded a package that required I reboot my device. I hit the reboot device button, forgetting about the tethered thing and got the stuck apple logo. So I plugged and used the Just Boot option on redsn0w. It booted up ok, except everything was like I never jailbroke it. I still have the Cydia app store and other jailbroken apps, but no jb settings, and themes don't work. Essentially, it's as if I have a non-jailbroken device with a few jailbroken apps.
And just like that it's right again. I think what happened was: something goofed when I downloaded Dreamboard. I got the Dreamboard icon on my home screen, but it wasn't in my packages. Just redownloaded it. Worked like a charm.
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