I would like to know where to go in iFile to be able to see your ipod passcode and be able to change the 4 digit code through iFile. I am running iOS 5.0.1.
It should be, is for sure in iOS6 and will ever be encrypted in future iOS versions. I doubt you can bypass the code.
However there is a securityleak in iOS 5 (since you have 5.0.1) I think you should check out this post online
The post contains this video, on how to bypass the lock. I hope that will help you out rather than changing the code via iFile.