Cory, you are my last hope. Afraid I've screwed myself. I rooted my Fascinate right after I got it in November when my Treo 650 finally died. Used your method in Terminal on Mac, but I found it in a blog where Sterling Cobb re-posted, but the un-root part was not there. So now that DL30 is out I looked for a way to un-root with little joy, trying to avoid PC - Odin (I'm a Mac guy, IT Admin in Mac shop). Ended up hosing it, tried using recovery mode reset to factory, now it has 2 force close loops, process.android.media and TwLauncher (process.com.sec.andriod.app.twlauncher) that make it unusable. I now suspect that the reset (ran all, apply sdcard:update.zip fails with "E:failed to verify whole-file signature", "E:signature verification failed", "Installation aborted.") knocked out USB debugging mode so can't get Odin, Heimdall, or terminal to connect, and can't get to settings to set USB debugging. I was hoping that something like you describe in post #5 above using update.zip in recovery might save me. Any chance?