sudo will not authenticate when trying to apt-get

[Ropetin Again]

Binary package hint: sudo

Running on Edgy with all the latest updates, specifically;

Sudo version 1.6.8p12
apt 0.6.45ubuntu14.2 for linux i386 compiled on Feb 23 2007 11:09:53

When I attempt to run 'sudo apt-get update', I get asked for my password, as it should. However, it will not accept my standard login password. I verify that I don't have caps-lock on, although I try it with and without caps-lock anyway, and it always fails. It uses only lower-case letters and numerical characters. If however I do sudo something else (usually 'sudo ls'), it will accept this password, remember I'm authenticated, and then let me 'sudo apt-get update' without putting in my password.

If I then let my sudo time expire (or 'sudo -k) and try 'sudo apt-get update' again, it will accept my password fine. It seems to happen intermittently, or potentially only after a reboot. It has, however, happened 10+ times now, so I know it is definitely not me typing something incorrectly.

[Ropetin Again (ropetin)]

I'm still unable to find a pattern to when this happens, but I know closer what the issue actually is. If I type the password and press enter, it fails. If, however, I enter the password and press enter twice, it accepts it. Weird.

[Ropetin Again (ropetin)]

There still doesn't appear to be a pattern to this, but I can definitely tell the difference between when it works and when it doesn't.

When sudo 'works', I put in the incorrect password (which I do a lot because I have many different passwords), it tells me;

Sorry, try again.

When sudo doesn't 'work', I put in the password, and it doesn't give any error or message, simply drops to the next line and asks for the password again. It will do this twice (i.e. I type my password 3 times) it will then give me the;

Sorry, try again.

Message.

I have Winbind installed and configured on this machine, to authenticate on a Domain, although when this happens I'm authenticating locally. Maybe that could be causing this issue?

[Ropetin Again (ropetin)]

I'm going to assume this was my fault, probably related to authenticating on a Domain, and having two identical user names. So I'll close the bug.