Comment 48 for bug 477169

Sorry Garik: In your PM, I missed the part about it being an old root.disk (or it didn't register, anyway).
Sounds like you probably already backed up your data too, and only want to use your old root.disk again.
Which root.disk is it that had the kernel error? If its the old one, then you definitely shouldn't replace the new with the old (at least not without backing up the new first), or its possible you'll need to reinstall with Wubi again.
If its the new one that's getting the error, then yeah, just go ahead, and replace it.