XP loses my login password

Note: this is NOT a 'rule 6' question. I don't want/need to break into my computer.

I ran an open system - no passwords required - for a few years. A couple of weeks ago, I passworded my admin and my personal (admin-level) accounts. It's a laptop, which I suspend between sessions. I typically re-boot after a week or two, but occasionally oftener, eg., as required by an MS update or some random weird behavior, but it's generally been quite stable.

Since I've passworded the accounts, it seems that after some number of sleep/wake cycles, the OS refuses my password. Rebooting fixes it - it allow me in again with my current password.

This evening when it happened after only 3 -5 sleep/wake cycles, restarted (warm booted) the machine. Only the admin account showed on the initial screen! So I logged into my admin account (successfully). From there, I looked at the User Accounts screen and it also did not show my personal account, only the admin account.

I cold booted, which brought everything back, and I could log into my personal account as usual (I'm using it now).

Having used XP pro a great deal at clients' sites on their machines & networks, and always with passworded accounts, I have never seen this behavior. If it helps any, those machines were always configured to require typing Ctrl-Alt-Delete and entering my user-name (usually pre-filled-in though) and password. My machine is not so configured - on my machine, all accounts appear on the initial screen and I click my own icon to begin logging in.

My clients' machines are desktops, re-booted every morning, and not suspended but locked with the Windows-L key or a timed screen-saver, and without my logging out, a dozen or twenty times a day. I suspend my laptop, also without logging out or locking it first, at least that often.

What causes this apparent temporary loss of my password by the OS?

Dell Inspiron 2650
XP Pro, SP2
No suspected issues, such as virii, etc.

Edit 8/2: add paragraph 7 re: locking / suspending without logging out.

 

Hmmm ..... check the password policy settings.

Administrative Tools>Local Security Policy>Account Policies>Password policy

Further check Password settings at Administrative Tools>Computer Management>Local Users and Groups>Users>double click username

Maybe someone else will have a better idea

 

OK - nothing unusual there. The General tab has Never Expire ticked (intentionally), and the Profile tab is empty.

 

Solved

I had been locked out, not forgotten. When it happened again this morning, I waited for the lockout period and was then able to log in.

XP gives the same message for (a possibly correct) password entry attempt during the lockout period ( "Did you forget your password? ") it gives for entering the wrong password. I had been typing my password carefully enough to be confident I'd entered it correctly, getting the above message, and, not realizing I was locked out, so I'd assumed it was XP's error. Of course, a re-boot reset everything.