On Corona 4g consoles I almost always get an error reading a block or 2 during both reads.
So when so you see this, just let it continue, there is a reason why we read twice, that is because if we had a crap connection for some reason, usually bad soldering, we would likely end up with a incomplete read and even if Jrunner didn't detect the bad read and just carried on reading and saving the nand to your PC, you wouldn't know and then if you assume that's good, and for whatever reason flashed it back, you'd be in some serious trouble. Reading twice is plenty, although reading 3 times would be more of a guarantee and give you a warm feeling inside that your dump is good. So anywho.. If you read the nand 2 or more times and it gets the same "error reading block xx" both times, and Jrunner tells you that the "Nands are the same", you're more than likely to go ahead and write Xell to obtain CPUKEY and proceed to decrypt and build your new image and flash back.
If you're experiencing this, as described above, then you are safe to go ahead and just continue with the next step, as the chances of getting multiple bad reads (even just 2 ) that match is practically impossible. If that happened to you, you'd be the unluckiest person in the world, lol. As long as you see it says "Nands are the same", you're more than likely fine, I chance it all the time with tons of send ins and it never goes wrong.
So go ahead and continue with the installation and move forward, you're probably fine, your xbox will be RGH'd soon.
