Another login issue – apparently stemming from the database…

Ok, I’ve had numerous login issues in the past with wordpress, the slightest change to something and seems the gates get shut :-/ All the past issues have been resolved and I’ve been able to login with no issues for months. However, over the last couple weeks I’ve been having more login problems – more specifically it takes up to 6 attempts before I’m able to login successfully, that’s up to 3 browser sessions as the Sentinel plugin kicks in after the second failed login and freezes my browser forcing me to shut it down manually then fire it back up again.

On a failed attempt, I receive the standard wordpress login error page with the login form and this message:

[Error log moderated as per the Forum Rules. Please use the pastebin]

I assumed it was an issue with the wp_useronline table, but after looking at it I couldn’t figure out what should be changed – if anything. There are also references – mainly in the first entry – to things that should have no effect on the login process (such as the “sinboard” page)…those could just be unrelated errors though.

Anyone got an idea how to resolve this?

Thanks in advance,

Lee C

P.S.
Just to add – when entering the username/password I did so manually by typing each character into the boxes, no copy/paste. This is why I know for a fact that the password is identical each time I enter it, whether it fails or succeeds, it’s the same password with each character in the same case.