whenever I use sudo i get "sudo: unable to cache user root, already exists"

Hey everyone,

I have installed a HD in my dvd drive bay and I was trying to dial down the disk idle time. I have done it in the past no problem. But now whenever I try to use sudo i get this message

sudo: unable to cache user root, already exists

now if i type like sudo -a or any of the sudo menu commands it brings up the help.

I think it may have something to do with being tech ******** and deleting the "system administrator" from the directory utility. Is there a way to get it back?

any help would be appreciated, thank you!!

Kris