sudo (Which I have configured to ask for a password) is rejecting my password (as if I mis-typed it) I am absolutely not typing it incorrectly. I have changed the password temporarily to alphabetic characters only, and it looks fine in plaintext, in the same terminal. I have my username configured thus:

myusername ALL=(ALL) ALL

I am using my password, NOT the root password, which are distinct. Just to be sure, I've tried both (even though I know the root password is not what I should use) - neither work.

I have added myself to the group 'wheel' additionally, and included the following line:

%wheel ALL=(ALL) ALL

I'm kind of at the end of my rope here. I don't know what would cause it to act as though it was accepting my password, but then reject it. I have no trouble logging in with the same password, either at terminal shells, or through the X11 login manager.