You know that little aside I made in this post, about how helpful it can be to reset your computer password from your install CD/DVD?
Welllll…that’s not the end of the story.
I found that that same password I couldn’t remember for my computer had been embedded – separately – in my default “login” keychain. I couldn’t add anything to that keychain or change anything about it, including the password, even after I reset my computer password!
The solution was to delete the keychain and all the data associated with it, and then reset my keychains to their default state with the new password. Could have been a real pain, if I’d had a lot of entries for that keychain. I didn’t, so I was lucky.
Just an FYI.
Weaponized Fluff 
I think it’s a good thing — I wouldn’t want a stranger having access to my keychain if they happened to get my laptop, and reset the password. At least they’d be limited to what info they could access, then.